Sample records for validated fe model
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Development and Validation of Accident Models for FeCrAl Cladding
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gamble, Kyle Allan Lawrence; Hales, Jason Dean
2016-08-01
The purpose of this milestone report is to present the work completed in regards to material model development for FeCrAl cladding and highlight the results of applying these models to Loss of Coolant Accidents (LOCA) and Station Blackouts (SBO). With the limited experimental data available (essentially only the data used to create the models) true validation is not possible. In the absence of another alternative, qualitative comparisons during postulated accident scenarios between FeCrAl and Zircaloy-4 cladded rods have been completed demonstrating the superior performance of FeCrAl.
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Development and validation of age-dependent FE human models of a mid-sized male thorax.
El-Jawahri, Raed E; Laituri, Tony R; Ruan, Jesse S; Rouhana, Stephen W; Barbat, Saeed D
2010-11-01
The increasing number of people over 65 years old (YO) is an important research topic in the area of impact biomechanics, and finite element (FE) modeling can provide valuable support for related research. There were three objectives of this study: (1) Estimation of the representative age of the previously-documented Ford Human Body Model (FHBM) -- an FE model which approximates the geometry and mass of a mid-sized male, (2) Development of FE models representing two additional ages, and (3) Validation of the resulting three models to the extent possible with respect to available physical tests. Specifically, the geometry of the model was compared to published data relating rib angles to age, and the mechanical properties of different simulated tissues were compared to a number of published aging functions. The FHBM was determined to represent a 53-59 YO mid-sized male. The aforementioned aging functions were used to develop FE models representing two additional ages: 35 and 75 YO. The rib model was validated against human rib specimens and whole rib tests, under different loading conditions, with and without modeled fracture. In addition, the resulting three age-dependent models were validated by simulating cadaveric tests of blunt and sled impacts. The responses of the models, in general, were within the cadaveric response corridors. When compared to peak responses from individual cadavers similar in size and age to the age-dependent models, some responses were within one standard deviation of the test data. All the other responses, but one, were within two standard deviations.
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Modelling human skull growth: a validated computational model
Marghoub, Arsalan; Johnson, David; Khonsari, Roman H.; Fagan, Michael J.; Moazen, Mehran
2017-01-01
During the first year of life, the brain grows rapidly and the neurocranium increases to about 65% of its adult size. Our understanding of the relationship between the biomechanical forces, especially from the growing brain, the craniofacial soft tissue structures and the individual bone plates of the skull vault is still limited. This basic knowledge could help in the future planning of craniofacial surgical operations. The aim of this study was to develop a validated computational model of skull growth, based on the finite-element (FE) method, to help understand the biomechanics of skull growth. To do this, a two-step validation study was carried out. First, an in vitro physical three-dimensional printed model and an in silico FE model were created from the same micro-CT scan of an infant skull and loaded with forces from the growing brain from zero to two months of age. The results from the in vitro model validated the FE model before it was further developed to expand from 0 to 12 months of age. This second FE model was compared directly with in vivo clinical CT scans of infants without craniofacial conditions (n = 56). The various models were compared in terms of predicted skull width, length and circumference, while the overall shape was quantified using three-dimensional distance plots. Statistical analysis yielded no significant differences between the male skull models. All size measurements from the FE model versus the in vitro physical model were within 5%, with one exception showing a 7.6% difference. The FE model and in vivo data also correlated well, with the largest percentage difference in size being 8.3%. Overall, the FE model results matched well with both the in vitro and in vivo data. With further development and model refinement, this modelling method could be used to assist in preoperative planning of craniofacial surgery procedures and could help to reduce reoperation rates. PMID:28566514
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Modelling human skull growth: a validated computational model.
Libby, Joseph; Marghoub, Arsalan; Johnson, David; Khonsari, Roman H; Fagan, Michael J; Moazen, Mehran
2017-05-01
During the first year of life, the brain grows rapidly and the neurocranium increases to about 65% of its adult size. Our understanding of the relationship between the biomechanical forces, especially from the growing brain, the craniofacial soft tissue structures and the individual bone plates of the skull vault is still limited. This basic knowledge could help in the future planning of craniofacial surgical operations. The aim of this study was to develop a validated computational model of skull growth, based on the finite-element (FE) method, to help understand the biomechanics of skull growth. To do this, a two-step validation study was carried out. First, an in vitro physical three-dimensional printed model and an in silico FE model were created from the same micro-CT scan of an infant skull and loaded with forces from the growing brain from zero to two months of age. The results from the in vitro model validated the FE model before it was further developed to expand from 0 to 12 months of age. This second FE model was compared directly with in vivo clinical CT scans of infants without craniofacial conditions ( n = 56). The various models were compared in terms of predicted skull width, length and circumference, while the overall shape was quantified using three-dimensional distance plots. Statistical analysis yielded no significant differences between the male skull models. All size measurements from the FE model versus the in vitro physical model were within 5%, with one exception showing a 7.6% difference. The FE model and in vivo data also correlated well, with the largest percentage difference in size being 8.3%. Overall, the FE model results matched well with both the in vitro and in vivo data. With further development and model refinement, this modelling method could be used to assist in preoperative planning of craniofacial surgery procedures and could help to reduce reoperation rates. © 2017 The Author(s).
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Thermodynamic modeling and experimental validation of the Fe-Al-Ni-Cr-Mo alloy system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Teng, Zhenke; Zhang, F; Miller, Michael K
2012-01-01
NiAl-type precipitate-strengthened ferritic steels have been known as potential materials for the steam turbine applications. In this study, thermodynamic descriptions of the B2-NiAl type nano-scaled precipitates and body-centered-cubic (BCC) Fe matrix phase for four alloys based on the Fe-Al-Ni-Cr-Mo system were developed as a function of the alloy composition at the aging temperature. The calculated phase structure, composition, and volume fraction were validated by the experimental investigations using synchrotron X-ray diffraction and atom probe tomography. With the ability to accurately predict the key microstructural features related to the mechanical properties in a given alloy system, the established thermodynamic model inmore » the current study may significantly accelerate the alloy design process of the NiAl-strengthened ferritic steels.« less
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Amiri, Sorosh; Naserkhaki, Sadegh; Parnianpour, Mohamad
2018-06-19
The dummies currently used for predicting vehicle occupant response during frontal crashes or whole-body vibration provide insufficient information about spinal loads. Although they aptly approximate upper-body rotations in different loading scenarios, they overlook spinal loads, which are crucial to injury assessment. This paper aims to develop a modified dummy finite element (FE) model with a detailed viscoelastic lumbar spine. This model has been developed and validated against in-vitro and in-silico data under different loading conditions, and its predicted ranges of motion (RoM) and intradiscal pressure (IDP) maintain close correspondence with the in-vitro data. The dominant frequency of the model was f = 8.92 Hz, which was close to previous results. In the relaxation test, a force reduction of up to 21% was obtained, showing high agreement in force relaxation during the in-vitro test. The FE lumbar spine model was placed in the HYBRID III test dummy and aligned in a seated position based on available MRI data. Under two impulsive acceleration loadings in flexion and lateral directions with a peak acceleration of 60 m/s 2 , flexion responses of the modified and original dummies were close (RoMs of 29.1° and 29.6°, respectively), though not in lateral bending (RoMs of 34.1° and 15.6°, respectively), where the modified dummy was more flexible than the original. By reconstructing a real frontal crash, it was found that the modified dummy provided a 10% reduction in the Head Injury Criterion (HIC). Other than the more realistic behavior of this modified dummy, its capability of approximating lumbar loads and risk of lumbar spine injuries in vehicle crashes or whole-body vibration is of great importance. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Roth, Sébastien; Torres, Fabien; Feuerstein, Philippe; Thoral-Pierre, Karine
2013-05-01
Finite element analysis is frequently used in several fields such as automotive simulations or biomechanics. It helps researchers and engineers to understand the mechanical behaviour of complex structures. The development of computer science brought the possibility to develop realistic computational models which can behave like physical ones, avoiding the difficulties and costs of experimental tests. In the framework of biomechanics, lots of FE models have been developed in the last few decades, enabling the investigation of the behaviour of the human body submitted to heavy damage such as in road traffic accidents or in ballistic impact. In both cases, the thorax/abdomen/pelvis system is frequently injured. The understanding of the behaviour of this complex system is of extreme importance. In order to explore the dynamic response of this system to impact loading, a finite element model of the human thorax/abdomen/pelvis system has, therefore, been developed including the main organs: heart, lungs, kidneys, liver, spleen, the skeleton (with vertebrae, intervertebral discs, ribs), stomach, intestines, muscles, and skin. The FE model is based on a 3D reconstruction, which has been made from medical records of anonymous patients, who have had medical scans with no relation to the present study. Several scans have been analyzed, and specific attention has been paid to the anthropometry of the reconstructed model, which can be considered as a 50th percentile male model. The biometric parameters and laws have been implemented in the dynamic FE code (Radioss, Altair Hyperworks 11©) used for dynamic simulations. Then the 50th percentile model was validated against experimental data available in the literature, in terms of deflection, force, whose curve must be in experimental corridors. However, for other anthropometries (small male or large male models) question about the validation and results of numerical accident replications can be raised. Copyright © 2012 Elsevier
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Finite Element Model and Validation of Nasal Tip Deformation
Manuel, Cyrus T; Harb, Rani; Badran, Alan; Ho, David; Wong, Brian JF
2016-01-01
Nasal tip mechanical stability is important for functional and cosmetic nasal airway surgery. Palpation of the nasal tip provides information on tip strength to the surgeon, though it is a purely subjective assessment. Providing a means to simulate nasal tip deformation with a validated model can offer a more objective approach in understanding the mechanics and nuances of the nasal tip support and eventual nasal mechanics as a whole. Herein we present validation of a finite element (FE) model of the nose using physical measurements recorded using an ABS plastic-silicone nasal phantom. Three-dimensional photogrammetry was used to capture the geometry of the phantom at rest and while under steady state load. The silicone used to make the phantom was mechanically tested and characterized using a linear elastic constitutive model. Surface point clouds of the silicone and FE model were compared for both the loaded and unloaded state. The average Hausdorff distance between actual measurements and FE simulations across the nose were 0.39mm ± 1.04 mm and deviated up to 2mm at the outermost boundaries of the model. FE simulation and measurements were in near complete agreement in the immediate vicinity of the nasal tip with millimeter accuracy. We have demonstrated validation of a two-component nasal FE model, which could be used to model more complex modes of deformation where direct measurement may be challenging. This is the first step in developing a nasal model to simulate nasal mechanics and ultimately the interaction between geometry and airflow. PMID:27633018
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Finite Element Model and Validation of Nasal Tip Deformation.
Manuel, Cyrus T; Harb, Rani; Badran, Alan; Ho, David; Wong, Brian J F
2017-03-01
Nasal tip mechanical stability is important for functional and cosmetic nasal airway surgery. Palpation of the nasal tip provides information on tip strength to the surgeon, though it is a purely subjective assessment. Providing a means to simulate nasal tip deformation with a validated model can offer a more objective approach in understanding the mechanics and nuances of the nasal tip support and eventual nasal mechanics as a whole. Herein we present validation of a finite element (FE) model of the nose using physical measurements recorded using an ABS plastic-silicone nasal phantom. Three-dimensional photogrammetry was used to capture the geometry of the phantom at rest and while under steady state load. The silicone used to make the phantom was mechanically tested and characterized using a linear elastic constitutive model. Surface point clouds of the silicone and FE model were compared for both the loaded and unloaded state. The average Hausdorff distance between actual measurements and FE simulations across the nose were 0.39 ± 1.04 mm and deviated up to 2 mm at the outermost boundaries of the model. FE simulation and measurements were in near complete agreement in the immediate vicinity of the nasal tip with millimeter accuracy. We have demonstrated validation of a two-component nasal FE model, which could be used to model more complex modes of deformation where direct measurement may be challenging. This is the first step in developing a nasal model to simulate nasal mechanics and ultimately the interaction between geometry and airflow.
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A Validated Open-Source Multisolver Fourth-Generation Composite Femur Model.
MacLeod, Alisdair R; Rose, Hannah; Gill, Harinderjit S
2016-12-01
Synthetic biomechanical test specimens are frequently used for preclinical evaluation of implant performance, often in combination with numerical modeling, such as finite-element (FE) analysis. Commercial and freely available FE packages are widely used with three FE packages in particular gaining popularity: abaqus (Dassault Systèmes, Johnston, RI), ansys (ANSYS, Inc., Canonsburg, PA), and febio (University of Utah, Salt Lake City, UT). To the best of our knowledge, no study has yet made a comparison of these three commonly used solvers. Additionally, despite the femur being the most extensively studied bone in the body, no freely available validated model exists. The primary aim of the study was primarily to conduct a comparison of mesh convergence and strain prediction between the three solvers (abaqus, ansys, and febio) and to provide validated open-source models of a fourth-generation composite femur for use with all the three FE packages. Second, we evaluated the geometric variability around the femoral neck region of the composite femurs. Experimental testing was conducted using fourth-generation Sawbones® composite femurs instrumented with strain gauges at four locations. A generic FE model and four specimen-specific FE models were created from CT scans. The study found that the three solvers produced excellent agreement, with strain predictions being within an average of 3.0% for all the solvers (r2 > 0.99) and 1.4% for the two commercial codes. The average of the root mean squared error against the experimental results was 134.5% (r2 = 0.29) for the generic model and 13.8% (r2 = 0.96) for the specimen-specific models. It was found that composite femurs had variations in cortical thickness around the neck of the femur of up to 48.4%. For the first time, an experimentally validated, finite-element model of the femur is presented for use in three solvers. This model is freely available online along with all the supporting validation data.
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NASA Astrophysics Data System (ADS)
Bondin, Mark I.; Borg, Stacey J.; Cheah, Mun-Hon; Best, Stephen P.
2006-11-01
Thiolate-bridged diiron compounds that are related to the active site of the [Fe-Fe] hydrogenase enzyme have been shown to act as electrocatalysts for reduction of protons. The use of XAFS for clarification of the structures of intermediates formed following reduction of related diiron carbonyl compounds is described. These measurements allow the determination of Fe-Fe and Fe-S bond lengths with good reliability and when used in conjunction with the standard bonding models this provides a means of validating the structures proposed for longer-lived ( t>20 s at -50 °C) reaction intermediates.
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Optimization and validation of FePro cell labeling method.
Janic, Branislava; Rad, Ali M; Jordan, Elaine K; Iskander, A S M; Ali, Md M; Varma, N Ravi S; Frank, Joseph A; Arbab, Ali S
2009-06-11
Current method to magnetically label cells using ferumoxides (Fe)-protamine (Pro) sulfate (FePro) is based on generating FePro complexes in a serum free media that are then incubated overnight with cells for the efficient labeling. However, this labeling technique requires long (>12-16 hours) incubation time and uses relatively high dose of Pro (5-6 microg/ml) that makes large extracellular FePro complexes. These complexes can be difficult to clean with simple cell washes and may create low signal intensity on T2* weighted MRI that is not desirable. The purpose of this study was to revise the current labeling method by using low dose of Pro and adding Fe and Pro directly to the cells before generating any FePro complexes. Human tumor glioma (U251) and human monocytic leukemia cell (THP-1) lines were used as model systems for attached and suspension cell types, respectively and dose dependent (Fe 25 to 100 microg/ml and Pro 0.75 to 3 microg/ml) and time dependent (2 to 48 h) labeling experiments were performed. Labeling efficiency and cell viability of these cells were assessed. Prussian blue staining revealed that more than 95% of cells were labeled. Intracellular iron concentration in U251 cells reached approximately 30-35 pg-iron/cell at 24 h when labeled with 100 microg/ml of Fe and 3 microg/ml of Pro. However, comparable labeling was observed after 4 h across the described FePro concentrations. Similarly, THP-1 cells achieved approximately 10 pg-iron/cell at 48 h when labeled with 100 microg/ml of Fe and 3 microg/ml of Pro. Again, comparable labeling was observed after 4 h for the described FePro concentrations. FePro labeling did not significantly affect cell viability. There was almost no extracellular FePro complexes observed after simple cell washes. To validate and to determine the effectiveness of the revised technique, human T-cells, human hematopoietic stem cells (hHSC), human bone marrow stromal cells (hMSC) and mouse neuronal stem cells (mNSC C17
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Reduction of Fe(III) colloids by Shewanella putrefaciens: A kinetic model
NASA Astrophysics Data System (ADS)
Bonneville, Steeve; Behrends, Thilo; van Cappellen, Philippe; Hyacinthe, Christelle; Röling, Wilfred F. M.
2006-12-01
A kinetic model for the microbial reduction of Fe(III) oxyhydroxide colloids in the presence of excess electron donor is presented. The model assumes a two-step mechanism: (1) attachment of Fe(III) colloids to the cell surface and (2) reduction of Fe(III) centers at the surface of attached colloids. The validity of the model is tested using Shewanella putrefaciens and nanohematite as model dissimilatory iron reducing bacteria and Fe(III) colloidal particles, respectively. Attachment of nanohematite to the bacteria is formally described by a Langmuir isotherm. Initial iron reduction rates are shown to correlate linearly with the relative coverage of the cell surface by nanohematite particles, hence supporting a direct electron transfer from membrane-bound reductases to mineral particles attached to the cells. Using internally consistent parameter values for the maximum attachment capacity of Fe(III) colloids to the cells, Mmax, the attachment constant, KP, and the first-order Fe(III) reduction rate constant, k, the model reproduces the initial reduction rates of a variety of fine-grained Fe(III) oxyhydroxides by S. putrefaciens. The model explains the observed dependency of the apparent Fe(III) half-saturation constant, Km∗, on the solid to cell ratio, and it predicts that initial iron reduction rates exhibit saturation with respect to both the cell density and the abundance of the Fe(III) oxyhydroxide substrate.
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On the validity of specific rate constants (kSA) in Fe0/H2O systems.
Noubactep, C
2009-05-30
The validity of the specific reaction rate constants (k(SA)) in modelling contaminant removal in Fe(0)/H(2)O systems is questioned. It is shown that the current k(SA)-model does not consider the large reactive surface area provided by the in-situ formed oxide film, and thus the adsorptive interactions between contaminants and film materials. Furthermore, neither the dynamic nature of film formation nor the fact that the Fe(0) surface is shielded by the film is considered. Suggestions are made how the k(SA)-model could be further developed to meet its original goal.
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NASA Astrophysics Data System (ADS)
Astroza, Rodrigo; Ebrahimian, Hamed; Li, Yong; Conte, Joel P.
2017-09-01
A methodology is proposed to update mechanics-based nonlinear finite element (FE) models of civil structures subjected to unknown input excitation. The approach allows to jointly estimate unknown time-invariant model parameters of a nonlinear FE model of the structure and the unknown time histories of input excitations using spatially-sparse output response measurements recorded during an earthquake event. The unscented Kalman filter, which circumvents the computation of FE response sensitivities with respect to the unknown model parameters and unknown input excitations by using a deterministic sampling approach, is employed as the estimation tool. The use of measurement data obtained from arrays of heterogeneous sensors, including accelerometers, displacement sensors, and strain gauges is investigated. Based on the estimated FE model parameters and input excitations, the updated nonlinear FE model can be interrogated to detect, localize, classify, and assess damage in the structure. Numerically simulated response data of a three-dimensional 4-story 2-by-1 bay steel frame structure with six unknown model parameters subjected to unknown bi-directional horizontal seismic excitation, and a three-dimensional 5-story 2-by-1 bay reinforced concrete frame structure with nine unknown model parameters subjected to unknown bi-directional horizontal seismic excitation are used to illustrate and validate the proposed methodology. The results of the validation studies show the excellent performance and robustness of the proposed algorithm to jointly estimate unknown FE model parameters and unknown input excitations.
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Development and validation of a 10-year-old child ligamentous cervical spine finite element model.
Dong, Liqiang; Li, Guangyao; Mao, Haojie; Marek, Stanley; Yang, King H
2013-12-01
Although a number of finite element (FE) adult cervical spine models have been developed to understand the injury mechanisms of the neck in automotive related crash scenarios, there have been fewer efforts to develop a child neck model. In this study, a 10-year-old ligamentous cervical spine FE model was developed for application in the improvement of pediatric safety related to motor vehicle crashes. The model geometry was obtained from medical scans and meshed using a multi-block approach. Appropriate properties based on review of literature in conjunction with scaling were assigned to different parts of the model. Child tensile force-deformation data in three segments, Occipital-C2 (C0-C2), C4-C5 and C6-C7, were used to validate the cervical spine model and predict failure forces and displacements. Design of computer experiments was performed to determine failure properties for intervertebral discs and ligaments needed to set up the FE model. The model-predicted ultimate displacements and forces were within the experimental range. The cervical spine FE model was validated in flexion and extension against the child experimental data in three segments, C0-C2, C4-C5 and C6-C7. Other model predictions were found to be consistent with the experimental responses scaled from adult data. The whole cervical spine model was also validated in tension, flexion and extension against the child experimental data. This study provided methods for developing a child ligamentous cervical spine FE model and to predict soft tissue failures in tension.
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Finite Element Model of the Knee for Investigation of Injury Mechanisms: Development and Validation
Kiapour, Ali; Kiapour, Ata M.; Kaul, Vikas; Quatman, Carmen E.; Wordeman, Samuel C.; Hewett, Timothy E.; Demetropoulos, Constantine K.; Goel, Vijay K.
2014-01-01
Multiple computational models have been developed to study knee biomechanics. However, the majority of these models are mainly validated against a limited range of loading conditions and/or do not include sufficient details of the critical anatomical structures within the joint. Due to the multifactorial dynamic nature of knee injuries, anatomic finite element (FE) models validated against multiple factors under a broad range of loading conditions are necessary. This study presents a validated FE model of the lower extremity with an anatomically accurate representation of the knee joint. The model was validated against tibiofemoral kinematics, ligaments strain/force, and articular cartilage pressure data measured directly from static, quasi-static, and dynamic cadaveric experiments. Strong correlations were observed between model predictions and experimental data (r > 0.8 and p < 0.0005 for all comparisons). FE predictions showed low deviations (root-mean-square (RMS) error) from average experimental data under all modes of static and quasi-static loading, falling within 2.5 deg of tibiofemoral rotation, 1% of anterior cruciate ligament (ACL) and medial collateral ligament (MCL) strains, 17 N of ACL load, and 1 mm of tibiofemoral center of pressure. Similarly, the FE model was able to accurately predict tibiofemoral kinematics and ACL and MCL strains during simulated bipedal landings (dynamic loading). In addition to minimal deviation from direct cadaveric measurements, all model predictions fell within 95% confidence intervals of the average experimental data. Agreement between model predictions and experimental data demonstrates the ability of the developed model to predict the kinematics of the human knee joint as well as the complex, nonuniform stress and strain fields that occur in biological soft tissue. Such a model will facilitate the in-depth understanding of a multitude of potential knee injury mechanisms with special emphasis on ACL injury
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NASA Astrophysics Data System (ADS)
Reina, Celia; Conti, Sergio
2017-10-01
The multiplicative decomposition of the total deformation F =FeFi between an elastic (Fe) and an inelastic component (Fi) is standard in the modeling of many irreversible processes such as plasticity, growth, thermoelasticity, viscoelasticty or phase transformations. The heuristic argument for such kinematic assumption is based on the chain rule for the compatible scenario (CurlFi = 0) where the individual deformation tensors are gradients of deformation mappings, i.e. F = D φ = D (φe ∘φi) = (Dφe) ∘φi (Dφi) =FeFi . Yet, the conditions for its validity in the general incompatible case (CurlFi ≠ 0) has so far remained uncertain. We show in this paper that detFi = 1 and CurlFi bounded are necessary and sufficient conditions for the validity of F =FeFi for a wide range of inelastic processes. In particular, in the context of crystal plasticity, we demonstrate via rigorous homogenization from discrete dislocations to the continuum level in two dimensions, that the volume preserving property of the mechanistics of dislocation glide, combined with a finite dislocation density, is sufficient to deliver F =FeFp at the continuum scale. We then generalize this result to general two-dimensional inelastic processes that may be described at a lower dimensional scale via a multiplicative decomposition while exhibiting a finite density of incompatibilities. The necessity of the conditions detFi = 1 and CurlFi bounded for such systems is demonstrated via suitable counterexamples.
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EIT image reconstruction based on a hybrid FE-EFG forward method and the complete-electrode model.
Hadinia, M; Jafari, R; Soleimani, M
2016-06-01
This paper presents the application of the hybrid finite element-element free Galerkin (FE-EFG) method for the forward and inverse problems of electrical impedance tomography (EIT). The proposed method is based on the complete electrode model. Finite element (FE) and element-free Galerkin (EFG) methods are accurate numerical techniques. However, the FE technique has meshing task problems and the EFG method is computationally expensive. In this paper, the hybrid FE-EFG method is applied to take both advantages of FE and EFG methods, the complete electrode model of the forward problem is solved, and an iterative regularized Gauss-Newton method is adopted to solve the inverse problem. The proposed method is applied to compute Jacobian in the inverse problem. Utilizing 2D circular homogenous models, the numerical results are validated with analytical and experimental results and the performance of the hybrid FE-EFG method compared with the FE method is illustrated. Results of image reconstruction are presented for a human chest experimental phantom.
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Development, Validation and Parametric study of a 3-Year-Old Child Head Finite Element Model
NASA Astrophysics Data System (ADS)
Cui, Shihai; Chen, Yue; Li, Haiyan; Ruan, ShiJie
2015-12-01
Traumatic brain injury caused by drop and traffic accidents is an important reason for children's death and disability. Recently, the computer finite element (FE) head model has been developed to investigate brain injury mechanism and biomechanical responses. Based on CT data of a healthy 3-year-old child head, the FE head model with detailed anatomical structure was developed. The deep brain structures such as white matter, gray matter, cerebral ventricle, hippocampus, were firstly created in this FE model. The FE model was validated by comparing the simulation results with that of cadaver experiments based on reconstructing the child and adult cadaver experiments. In addition, the effects of skull stiffness on the child head dynamic responses were further investigated. All the simulation results confirmed the good biofidelity of the FE model.
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NASA Astrophysics Data System (ADS)
Singh, Sarabjeet; Howard, Carl Q.; Hansen, Colin H.; Köpke, Uwe G.
2018-03-01
In this paper, numerically modelled vibration response of a rolling element bearing with a localised outer raceway line spall is presented. The results were obtained from a finite element (FE) model of the defective bearing solved using an explicit dynamics FE software package, LS-DYNA. Time domain vibration signals of the bearing obtained directly from the FE modelling were processed further to estimate time-frequency and frequency domain results, such as spectrogram and power spectrum, using standard signal processing techniques pertinent to the vibration-based monitoring of rolling element bearings. A logical approach to analyses of the numerically modelled results was developed with an aim to presenting the analytical validation of the modelled results. While the time and frequency domain analyses of the results show that the FE model generates accurate bearing kinematics and defect frequencies, the time-frequency analysis highlights the simulation of distinct low- and high-frequency characteristic vibration signals associated with the unloading and reloading of the rolling elements as they move in and out of the defect, respectively. Favourable agreement of the numerical and analytical results demonstrates the validation of the results from the explicit FE modelling of the bearing.
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NASA Astrophysics Data System (ADS)
Zhang, Jie; Nixon, Andrew; Barber, Tom; Budyn, Nicolas; Bevan, Rhodri; Croxford, Anthony; Wilcox, Paul
2018-04-01
In this paper, a methodology of using finite element (FE) model to validate a ray-based model in the simulation of full matrix capture (FMC) ultrasonic array data set is proposed. The overall aim is to separate signal contributions from different interactions in FE results for easier comparing each individual component in the ray-based model results. This is achieved by combining the results from multiple FE models of the system of interest that include progressively more geometrical features while preserving the same mesh structure. It is shown that the proposed techniques allow the interactions from a large number of different ray-paths to be isolated in FE results and compared directly to the results from a ray-based forward model.
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A strong pinning model for the coercivity of die-upset Pr-Fe-B magnets
NASA Astrophysics Data System (ADS)
Pinkerton, F. E.; fürst, C. D.
1991-04-01
We have measured the temperature dependence of the intrinsic coercivity Hci(T) between 5 and 565 K in a die-upset Pr-Fe-B magnet. Over a very wide temperature range up to 477 K, Hci(T) is in excellent agreement with a model for strong domain-wall pinning by a random array of pinning sites proposed by Gaunt [P. Gaunt, Philos. Mag. B 48, 261 (1983)]. The model includes both the temperature dependence of the intrinsic magnetic properties of the Pr2Fe14B phase and the effects of thermal activation of domain walls over the pinning barrier. The pinning sites are modeled as nonmagnetic planar inhomogeneities at the boundaries between platelet-shaped Pr2Fe14B grains. We develop an expression for the maximum pinning force per site, f, and derive the model prediction that (Hci/γHA)1/2 varies linearly with (T/γ)2/3, where HA and γ are the magnetocrystalline anisotropy field and the domain-wall energy per unit area of the Pr2Fe14B phase, respectively. Significant deviations from the model are observed only at high temperature, suggesting that the strong pinning model is no longer valid very close to the Curie temperature (565 K). The present result agrees with the model fit obtained for a die-upset Nd-Fe-B magnet.
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Comparison of Ab initio Low-Energy Models for LaFePO, LaFeAsO, BaFe2As2, LiFeAs, FeSe, and FeTe
NASA Astrophysics Data System (ADS)
Nakamura, Kazuma; Miyake, Takashi; Arita, Ryotaro; Imada, Masatoshi
2010-03-01
We present effective low-energy models for LaFePO and LaFeAsO (1111 family), BaFe2As2 (122), LiFeAs (111), and FeSe and FeTe (11) [1], based on ab initio downfolding scheme, a constrained random-phase-approximation method combined with maximally localized Wannier functions. Comparison among the effective models, derived for 5 Fe-3d bands, provides a basis for interpreting physics/chemistry; material dependences of electron correlations, a multiband character entangled by the 3d orbitals, and the geometrical frustration depending on hybridizations between iron and pnictogen/chalcogen orbitals. We found that LaFePO in the 1111 family resides in the weak correlation regime, while LaFeAsO and 111/122 compounds are the intermediate region and FeSe and FeTe in the 11 family are located in the strong correlation regime. A principal parameter relevant to the physics is clarified to be the pnictogen/chalcogen height from the iron layer. Implications in low-energy properties including magnetism and superconductivity are discussed. [1] T. Miyake, K. Nakamura, R. Arita, and M. Imada, arXiv:0911.3705.
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Model's sparse representation based on reduced mixed GMsFE basis methods
NASA Astrophysics Data System (ADS)
Jiang, Lijian; Li, Qiuqi
2017-06-01
In this paper, we propose a model's sparse representation based on reduced mixed generalized multiscale finite element (GMsFE) basis methods for elliptic PDEs with random inputs. A typical application for the elliptic PDEs is the flow in heterogeneous random porous media. Mixed generalized multiscale finite element method (GMsFEM) is one of the accurate and efficient approaches to solve the flow problem in a coarse grid and obtain the velocity with local mass conservation. When the inputs of the PDEs are parameterized by the random variables, the GMsFE basis functions usually depend on the random parameters. This leads to a large number degree of freedoms for the mixed GMsFEM and substantially impacts on the computation efficiency. In order to overcome the difficulty, we develop reduced mixed GMsFE basis methods such that the multiscale basis functions are independent of the random parameters and span a low-dimensional space. To this end, a greedy algorithm is used to find a set of optimal samples from a training set scattered in the parameter space. Reduced mixed GMsFE basis functions are constructed based on the optimal samples using two optimal sampling strategies: basis-oriented cross-validation and proper orthogonal decomposition. Although the dimension of the space spanned by the reduced mixed GMsFE basis functions is much smaller than the dimension of the original full order model, the online computation still depends on the number of coarse degree of freedoms. To significantly improve the online computation, we integrate the reduced mixed GMsFE basis methods with sparse tensor approximation and obtain a sparse representation for the model's outputs. The sparse representation is very efficient for evaluating the model's outputs for many instances of parameters. To illustrate the efficacy of the proposed methods, we present a few numerical examples for elliptic PDEs with multiscale and random inputs. In particular, a two-phase flow model in random porous
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Model's sparse representation based on reduced mixed GMsFE basis methods
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jiang, Lijian, E-mail: ljjiang@hnu.edu.cn; Li, Qiuqi, E-mail: qiuqili@hnu.edu.cn
2017-06-01
In this paper, we propose a model's sparse representation based on reduced mixed generalized multiscale finite element (GMsFE) basis methods for elliptic PDEs with random inputs. A typical application for the elliptic PDEs is the flow in heterogeneous random porous media. Mixed generalized multiscale finite element method (GMsFEM) is one of the accurate and efficient approaches to solve the flow problem in a coarse grid and obtain the velocity with local mass conservation. When the inputs of the PDEs are parameterized by the random variables, the GMsFE basis functions usually depend on the random parameters. This leads to a largemore » number degree of freedoms for the mixed GMsFEM and substantially impacts on the computation efficiency. In order to overcome the difficulty, we develop reduced mixed GMsFE basis methods such that the multiscale basis functions are independent of the random parameters and span a low-dimensional space. To this end, a greedy algorithm is used to find a set of optimal samples from a training set scattered in the parameter space. Reduced mixed GMsFE basis functions are constructed based on the optimal samples using two optimal sampling strategies: basis-oriented cross-validation and proper orthogonal decomposition. Although the dimension of the space spanned by the reduced mixed GMsFE basis functions is much smaller than the dimension of the original full order model, the online computation still depends on the number of coarse degree of freedoms. To significantly improve the online computation, we integrate the reduced mixed GMsFE basis methods with sparse tensor approximation and obtain a sparse representation for the model's outputs. The sparse representation is very efficient for evaluating the model's outputs for many instances of parameters. To illustrate the efficacy of the proposed methods, we present a few numerical examples for elliptic PDEs with multiscale and random inputs. In particular, a two-phase flow model in random
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NASA Astrophysics Data System (ADS)
Chu, Xinzhao; Yu, Zhibin
2017-06-01
With a thermosphere-ionosphere Fe/Fe+ (TIFe) model developed from first principles at the University of Colorado, we present the first quantitative investigation of formation mechanisms of thermospheric Fe layers observed by lidar in Antarctica. These recently discovered neutral metal layers in the thermosphere between 100 and 200 km provide unique tracers for studies of fundamental processes in the space-atmosphere interaction region. The TIFe model formulates and expands the TIFe theory originally proposed by Chu et al. that the thermospheric Fe layers are produced through the neutralization of converged Fe+ layers. Through testing mechanisms and reproducing the 28 May 2011 event at McMurdo, we conceive the lifecycle of meteoric metals via deposition, transport, chemistry, and wave dynamics for thermospheric Fe layers with gravity wave signatures. While the meteor injection of iron species is negligible above 120 km, the polar electric field transports metallic ions Fe+ upward from their main deposition region into the E-F regions, providing the major source of Fe+ (and accordingly Fe) in the thermosphere. Atmospheric wave-induced vertical shears of vertical and horizontal winds converge Fe+ to form dense Fe+ layers. Direct electron-Fe+ recombination is the major channel to neutralize Fe+ layers to form Fe above 120 km. Fe layer shapes are determined by multiple factors of neutral winds, electric field, and aurora activity. Gravity-wave-induced vertical wind plays a key role in forming gravity-wave-shaped Fe layers. Aurora particle precipitation enhances Fe+ neutralization by increasing electron density while accelerating Fe loss via charge transfer with enhanced NO+ and O2+ densities.
Plain Language SummaryThe discoveries of neutral metal layers reaching near 200 km in the thermosphere have significant scientific merit because such discoveries challenge the current understandings of upper atmospheric composition</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMDI43C..05R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMDI43C..05R"><span><span class="hlt">Modeling</span> (Mg,<span class="hlt">Fe</span>)O creep at Lowermost Mantle conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reali, R.; Jackson, J. M.; Van Orman, J. A.; Carrez, P.; Cordier, P.</p> <p>2017-12-01</p> <p>The viscosity of the lower mantle results from the rheological behavior of its two main constituent minerals, aluminous (Mg,<span class="hlt">Fe</span>)SiO3 bridgmanite and (Mg,<span class="hlt">Fe</span>)O ferropericlase. Understanding the rheology of lower mantle aggregates is of primary importance in geophysics and it is a challenging task, due to the extreme time-varying conditions to which such aggregates are subjected.Here we focus on the creep behavior of (Mg,<span class="hlt">Fe</span>)O at the bottom of the lower mantle, where the presence of thermo-chemical anomalies such as ultralow-velocity zones (ULVZ) can significantly alter the composition and therefore the properties of this region. Two different iron concentrations of (Mg1-xFex)O are considered: one mirroring the average composition of ferropericlase throughout most of the lower mantle (x = 0.20) and another representing a candidate component of ULVZs near the base of the mantle (x = 0.84) [1]. The investigated pressure-temperature conditions span from 120 GPa and 2800 K, corresponding to the geotherm at this depth, to core-mantle conditions of 135 GPa and 3800 K.In this study, dislocation creep of (Mg,<span class="hlt">Fe</span>)O is investigated by Dislocation Dynamics (DD) simulations, a <span class="hlt">modeling</span> tool which considers the collective motion and interactions of dislocations. To <span class="hlt">model</span> their behavior, a 2.5 Dimensional Dislocation Dynamics approach (2.5D-DD) is employed. Within this method, both glide and climb mechanisms can be taken into account, and the interplay of these features results in a steady-state condition. This allows the retrieval of the creep strain rates at different temperatures, pressures, applied stresses and iron concentrations across the (Mg,<span class="hlt">Fe</span>)O solid solution, providing information on the viscosity for these materials. This numerical approach has been <span class="hlt">validated</span> at ambient conditions, where it was benchmarked with respect to experimental data on MgO [2]. [1] J.K. Wicks, J.M. Jackson, W. Sturhahn and D. Zhang, GRL, 44, 2017.[2] R. Reali, F. Boioli, K. Gouriet, P. Carrez, B</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA620802','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA620802"><span>Experimental <span class="hlt">Validation</span> of the Butyl-Rubber Finite Element (<span class="hlt">FE</span>) Material <span class="hlt">Model</span> for the Blast-Mitigating Floor Mat</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-08-01</p> <p>Analysis ( FEA ) results of each <span class="hlt">FE</span>-material <span class="hlt">model</span>, and the errors in each material <span class="hlt">model</span> are discussed on various metrics. 15. SUBJECT TERMS ESEP... FEAs ...................................................................... 9 Fig. 8 Velocity histories on the loading table in FEAs for 4-millisecond...10 Fig. 9 Velocity histories on the loading table in FEAs for 8-msec-pulse loading ................... 10 Fig. 10 Velocity histories on</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17433333','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17433333"><span>Physical <span class="hlt">validation</span> of a patient-specific contact finite element <span class="hlt">model</span> of the ankle.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Anderson, Donald D; Goldsworthy, Jane K; Li, Wendy; James Rudert, M; Tochigi, Yuki; Brown, Thomas D</p> <p>2007-01-01</p> <p>A <span class="hlt">validation</span> study was conducted to determine the extent to which computational ankle contact finite element (<span class="hlt">FE</span>) results agreed with experimentally measured tibio-talar contact stress. Two cadaver ankles were loaded in separate test sessions, during which ankle contact stresses were measured with a high-resolution (Tekscan) pressure sensor. Corresponding contact <span class="hlt">FE</span> analyses were subsequently performed for comparison. The agreement was good between <span class="hlt">FE</span>-computed and experimentally measured mean (3.2% discrepancy for one ankle, 19.3% for the other) and maximum (1.5% and 6.2%) contact stress, as well as for contact area (1.7% and 14.9%). There was also excellent agreement between histograms of fractional areas of cartilage experiencing specific ranges of contact stress. Finally, point-by-point comparisons between the computed and measured contact stress distributions over the articular surface showed substantial agreement, with correlation coefficients of 90% for one ankle and 86% for the other. In the past, general qualitative, but little direct quantitative agreement has been demonstrated with articular joint contact <span class="hlt">FE</span> <span class="hlt">models</span>. The methods used for this <span class="hlt">validation</span> enable formal comparison of computational and experimental results, and open the way for objective statistical measures of regional correlation between <span class="hlt">FE</span>-computed contact stress distributions from comparison articular joint surfaces (e.g., those from an intact versus those with residual intra-articular fracture incongruity).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26126995','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26126995"><span>Statistical <span class="hlt">modeling</span> of the reactions <span class="hlt">Fe</span>(+) + N2O → <span class="hlt">Fe</span>O(+) + N2 and <span class="hlt">Fe</span>O(+) + CO → <span class="hlt">Fe</span>(+) + CO2.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ushakov, Vladimir G; Troe, Jürgen; Johnson, Ryan S; Guo, Hua; Ard, Shaun G; Melko, Joshua J; Shuman, Nicholas S; Viggiano, Albert A</p> <p>2015-08-14</p> <p>The rates of the reactions <span class="hlt">Fe</span>(+) + N2O → <span class="hlt">Fe</span>O(+) + N2 and <span class="hlt">Fe</span>O(+) + CO → <span class="hlt">Fe</span>(+) + CO2 are <span class="hlt">modeled</span> by statistical rate theory accounting for energy- and angular momentum-specific rate constants for formation of the primary and secondary cationic adducts and their backward and forward reactions. The reactions are both suggested to proceed on sextet and quartet potential energy surfaces with efficient, but probably not complete, equilibration by spin-inversion of the populations of the sextet and quartet adducts. The influence of spin-inversion on the overall reaction rate is investigated. The differences of the two reaction rates mostly are due to different numbers of entrance states (atom + linear rotor or linear rotor + linear rotor, respectively). The reaction <span class="hlt">Fe</span>(+) + N2O was studied either with (6)<span class="hlt">Fe</span>(+) or with (4)<span class="hlt">Fe</span>(+) reactants. Differences in the rate constants of (6)<span class="hlt">Fe</span>(+) and (4)<span class="hlt">Fe</span>(+) reacting with N2O are attributed to different contributions from electronically excited potential energy surfaces, such as they originate from the open-electronic shell reactants.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27047304','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27047304"><span>Orientation relationship of eutectoid <span class="hlt">Fe</span>Al and <span class="hlt">Fe</span>Al2.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scherf, A; Kauffmann, A; Kauffmann-Weiss, S; Scherer, T; Li, X; Stein, F; Heilmaier, M</p> <p>2016-04-01</p> <p><span class="hlt">Fe</span>-Al alloys in the aluminium range of 55-65 at.% exhibit a lamellar microstructure of B2-ordered <span class="hlt">Fe</span>Al and triclinic <span class="hlt">Fe</span>Al 2 , which is caused by a eutectoid decomposition of the high-temperature <span class="hlt">Fe</span> 5 Al 8 phase, the so-called ∊ phase. The orientation relationship of <span class="hlt">Fe</span>Al and <span class="hlt">Fe</span>Al 2 has previously been studied by Bastin et al. [ J. Cryst. Growth (1978 ▸), 43 , 745] and Hirata et al. [ Philos. Mag. Lett. (2008 ▸), 88 , 491]. Since both results are based on different crystallographic data regarding <span class="hlt">Fe</span>Al 2 , the data are re-evaluated with respect to a recent re-determination of the <span class="hlt">Fe</span>Al 2 phase provided by Chumak et al. [ Acta Cryst. (2010 ▸), C 66 , i87]. It is found that both orientation relationships match subsequent to a rotation operation of 180° about a 〈112〉 crystallographic axis of <span class="hlt">Fe</span>Al or by applying the inversion symmetry of the <span class="hlt">Fe</span>Al 2 crystal structure as suggested by the Chumak data set. Experimental evidence for the <span class="hlt">validity</span> of the previously determined orientation relationships was found in as-cast fully lamellar material (random texture) as well as directionally solidified material (∼〈110〉 <span class="hlt">Fe</span>Al || solidification direction) by means of orientation imaging microscopy and global texture measurements. In addition, a preferential interface between <span class="hlt">Fe</span>Al and <span class="hlt">Fe</span>Al 2 was identified by means of trace analyses using cross sectioning with a focused ion beam. On the basis of these habit planes the orientation relationship between the two phases can be described by ([Formula: see text]01) <span class="hlt">Fe</span>Al || (114)[Formula: see text] and [111] <span class="hlt">Fe</span>Al || [1[Formula: see text]0][Formula: see text]. There is no evidence for twinning within <span class="hlt">Fe</span>Al lamellae or alternating orientations of <span class="hlt">Fe</span>Al lamellae. Based on the determined orientation and interface data, an atomistic <span class="hlt">model</span> of the structure relationship of <span class="hlt">Fe</span> 5 Al 8 , <span class="hlt">Fe</span>Al and <span class="hlt">Fe</span>Al 2 in the vicinity of the eutectoid decomposition is derived. This <span class="hlt">model</span> is analysed with respect to the strain which has to be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3010399','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3010399"><span>Role of the Azadithiolate Cofactor in <span class="hlt">Models</span> for the [<span class="hlt">FeFe</span>]-Hydrogenase: Novel Structures and Catalytic Implications</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Olsen, Matthew T.; Rauchfuss, Thomas B.; Wilson, Scott R.</p> <p>2010-01-01</p> <p>The report summarizes studies on the redox behavior of synthetic <span class="hlt">models</span> for the [<span class="hlt">FeFe</span>]-hydrogenases, consisting of diiron dithiolato carbonyl complexes bearing the amine cofactor and its N-benzyl derivative. Of specific interest are the causes of the low reactivity of oxidized <span class="hlt">models</span> toward H2, which contrasts with the high activity of these enzymes for H2 oxidation. The redox and acid-base properties of the <span class="hlt">model</span> complexes [<span class="hlt">Fe</span>2[(SCH2)2NR](CO)3(dppv)(PMe3)]+ ([2]+ for R = H and [2′]+ for R = CH2C6H5, dppv = cis-1,2-bis(diphenylphosphino)ethylene)) indicate that addition of H2 and followed by deprotonation are (i) endothermic for the mixed valence (<span class="hlt">Fe</span>IIFeI) state and (ii) exothermic for the diferrous (<span class="hlt">Fe</span>IIFeII) state. The diferrous state is shown to be unstable with respect to coordination of the amine to <span class="hlt">Fe</span>, a derivative of which was characterized crystallographically. The redox and acid-base properties for the mixed valence <span class="hlt">models</span> differ strongly for those containing the amine cofactor versus those derived from propanedithiolate. Protonation of [2′]+ induces disproportionation to a 1:1 mixture of the ammonium-<span class="hlt">Fe</span>IFeI and the dication [2′]2+ (<span class="hlt">Fe</span>IIFeII). This effect is consistent with substantial enhancement of the basicity of the amine in the <span class="hlt">Fe</span>IFeI state vs the <span class="hlt">Fe</span>IIFeI state. The <span class="hlt">Fe</span>IFeI ammonium compounds are rapid and efficient H-atom donors toward the nitroxyl compound TEMPO. The atom transfer is proposed to proceed via the hydride, as indicated by the reaction of [HFe2[(SCH2)2NH](CO)2(dppv)2]+ with TEMPO. Collectively, the results suggest that proton-coupled electron-transfer pathways should be considered for H2 activation by the [<span class="hlt">FeFe</span>]-hydrogenases. PMID:21114298</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.896a2096S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.896a2096S"><span>Setup of a Parameterized <span class="hlt">FE</span> <span class="hlt">Model</span> for the Die Roll Prediction in Fine Blanking using Artificial Neural Networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stanke, J.; Trauth, D.; Feuerhack, A.; Klocke, F.</p> <p>2017-09-01</p> <p>Die roll is a morphological feature of fine blanked sheared edges. The die roll reduces the functional part of the sheared edge. To compensate for the die roll thicker sheet metal strips and secondary machining must be used. However, in order to avoid this, the influence of various fine blanking process parameters on the die roll has been experimentally and numerically studied, but there is still a lack of knowledge on the effects of some factors and especially factor interactions on the die roll. Recent changes in the field of artificial intelligence motivate the hybrid use of the finite element method and artificial neural networks to account for these non-considered parameters. Therefore, a set of simulations using a <span class="hlt">validated</span> finite element <span class="hlt">model</span> of fine blanking is firstly used to train an artificial neural network. Then the artificial neural network is trained with thousands of experimental trials. Thus, the objective of this contribution is to develop an artificial neural network that reliably predicts the die roll. Therefore, in this contribution, the setup of a fully parameterized 2D <span class="hlt">FE</span> <span class="hlt">model</span> is presented that will be used for batch training of an artificial neural network. The <span class="hlt">FE</span> <span class="hlt">model</span> enables an automatic variation of the edge radii of blank punch and die plate, the counter and blank holder force, the sheet metal thickness and part diameter, V-ring height and position, cutting velocity as well as material parameters covered by the Hensel-Spittel <span class="hlt">model</span> for 16MnCr5 (1.7131, AISI/SAE 5115). The <span class="hlt">FE</span> <span class="hlt">model</span> is <span class="hlt">validated</span> using experimental trails. The results of this contribution is a <span class="hlt">FE</span> <span class="hlt">model</span> suitable to perform 9.623 simulations and to pass the simulated die roll width and height automatically to an artificial neural network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28700618','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28700618"><span>Micro Finite Element <span class="hlt">models</span> of the vertebral body: <span class="hlt">Validation</span> of local displacement predictions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Costa, Maria Cristiana; Tozzi, Gianluca; Cristofolini, Luca; Danesi, Valentina; Viceconti, Marco; Dall'Ara, Enrico</p> <p>2017-01-01</p> <p>The estimation of local and structural mechanical properties of bones with micro Finite Element (micro<span class="hlt">FE</span>) <span class="hlt">models</span> based on Micro Computed Tomography images depends on the quality bone geometry is captured, reconstructed and <span class="hlt">modelled</span>. The aim of this study was to <span class="hlt">validate</span> micro<span class="hlt">FE</span> <span class="hlt">models</span> predictions of local displacements for vertebral bodies and to evaluate the effect of the elastic tissue modulus on <span class="hlt">model</span>'s predictions of axial forces. Four porcine thoracic vertebrae were axially compressed in situ, in a step-wise fashion and scanned at approximately 39μm resolution in preloaded and loaded conditions. A global digital volume correlation (DVC) approach was used to compute the full-field displacements. Homogeneous, isotropic and linear elastic micro<span class="hlt">FE</span> <span class="hlt">models</span> were generated with boundary conditions assigned from the interpolated displacement field measured from the DVC. Measured and predicted local displacements were compared for the cortical and trabecular compartments in the middle of the specimens. <span class="hlt">Models</span> were run with two different tissue moduli defined from microindentation data (12.0GPa) and a back-calculation procedure (4.6GPa). The predicted sum of axial reaction forces was compared to the experimental values for each specimen. Micro<span class="hlt">FE</span> <span class="hlt">models</span> predicted more than 87% of the variation in the displacement measurements (R2 = 0.87-0.99). However, <span class="hlt">model</span> predictions of axial forces were largely overestimated (80-369%) for a tissue modulus of 12.0GPa, whereas differences in the range 10-80% were found for a back-calculated tissue modulus. The specimen with the lowest density showed a large number of elements strained beyond yield and the highest predictive errors. This study shows that the simplest micro<span class="hlt">FE</span> <span class="hlt">models</span> can accurately predict quantitatively the local displacements and qualitatively the strain distribution within the vertebral body, independently from the considered bone types.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5507408','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5507408"><span>Micro Finite Element <span class="hlt">models</span> of the vertebral body: <span class="hlt">Validation</span> of local displacement predictions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Costa, Maria Cristiana; Tozzi, Gianluca; Cristofolini, Luca; Danesi, Valentina; Viceconti, Marco</p> <p>2017-01-01</p> <p>The estimation of local and structural mechanical properties of bones with micro Finite Element (micro<span class="hlt">FE</span>) <span class="hlt">models</span> based on Micro Computed Tomography images depends on the quality bone geometry is captured, reconstructed and <span class="hlt">modelled</span>. The aim of this study was to <span class="hlt">validate</span> micro<span class="hlt">FE</span> <span class="hlt">models</span> predictions of local displacements for vertebral bodies and to evaluate the effect of the elastic tissue modulus on model’s predictions of axial forces. Four porcine thoracic vertebrae were axially compressed in situ, in a step-wise fashion and scanned at approximately 39μm resolution in preloaded and loaded conditions. A global digital volume correlation (DVC) approach was used to compute the full-field displacements. Homogeneous, isotropic and linear elastic micro<span class="hlt">FE</span> <span class="hlt">models</span> were generated with boundary conditions assigned from the interpolated displacement field measured from the DVC. Measured and predicted local displacements were compared for the cortical and trabecular compartments in the middle of the specimens. <span class="hlt">Models</span> were run with two different tissue moduli defined from microindentation data (12.0GPa) and a back-calculation procedure (4.6GPa). The predicted sum of axial reaction forces was compared to the experimental values for each specimen. Micro<span class="hlt">FE</span> <span class="hlt">models</span> predicted more than 87% of the variation in the displacement measurements (R2 = 0.87–0.99). However, <span class="hlt">model</span> predictions of axial forces were largely overestimated (80–369%) for a tissue modulus of 12.0GPa, whereas differences in the range 10–80% were found for a back-calculated tissue modulus. The specimen with the lowest density showed a large number of elements strained beyond yield and the highest predictive errors. This study shows that the simplest micro<span class="hlt">FE</span> <span class="hlt">models</span> can accurately predict quantitatively the local displacements and qualitatively the strain distribution within the vertebral body, independently from the considered bone types. PMID:28700618</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140003595','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140003595"><span>Calibration and <span class="hlt">Validation</span> of a Finite ELement <span class="hlt">Model</span> of THor-K Anthropomorphic Test Device for Aerospace Safety Applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Putnam, J. B.; Unataroiu, C. D.; Somers, J. T.</p> <p>2014-01-01</p> <p>The THOR anthropomorphic test device (ATD) has been developed and continuously improved by the National Highway Traffic Safety Administration to provide automotive manufacturers an advanced tool that can be used to assess the injury risk of vehicle occupants in crash tests. Recently, a series of modifications were completed to improve the biofidelity of THOR ATD [1]. The updated THOR Modification Kit (THOR-K) ATD was employed at Wright-Patterson Air Base in 22 impact tests in three configurations: vertical, lateral, and spinal [2]. Although a computational finite element (<span class="hlt">FE</span>) <span class="hlt">model</span> of the THOR had been previously developed [3], updates to the <span class="hlt">model</span> were needed to incorporate the recent changes in the modification kit. The main goal of this study was to develop and <span class="hlt">validate</span> a <span class="hlt">FE</span> <span class="hlt">model</span> of the THOR-K ATD. The CAD drawings of the THOR-K ATD were reviewed and <span class="hlt">FE</span> <span class="hlt">models</span> were developed for the updated parts. For example, the head-skin geometry was found to change significantly, so its <span class="hlt">model</span> was re-meshed (Fig. 1a). A protocol was developed to calibrate each component identified as key to the kinematic and kinetic response of the THOR-K head/neck ATD <span class="hlt">FE</span> <span class="hlt">model</span> (Fig. 1b). The available ATD tests were divided in two groups: a) calibration tests where the unknown material parameters of deformable parts (e.g., head skin, pelvis foam) were optimized to match the data and b) <span class="hlt">validation</span> tests where the <span class="hlt">model</span> response was only compared with test data by calculating their score using CORrelation and Analysis (CORA) rating system. Finally, the whole ATD <span class="hlt">model</span> was <span class="hlt">validated</span> under horizontal-, vertical-, and lateral-loading conditions against data recorded in the Wright Patterson tests [2]. Overall, the final THOR-K ATD <span class="hlt">model</span> developed in this study is shown to respond similarly to the ATD in all <span class="hlt">validation</span> tests. This good performance indicates that the optimization performed during calibration by using the CORA score as objective function is not test specific. Therefore confidence is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21296047','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21296047"><span>On understanding proton transfer to the biocatalytic [<span class="hlt">Fe-Fe</span>](H) sub-cluster in [<span class="hlt">Fe-Fe</span>]H(2)ases: QM/MM MD simulations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hong, G; Cornish, A J; Hegg, E L; Pachter, R</p> <p>2011-05-01</p> <p>Proton transfer to the [<span class="hlt">Fe-Fe</span>](H) sub-cluster in the Desulfovibrio desulfuricans (DdH) and Clostridium pasteurianum (CpI) [<span class="hlt">Fe-Fe</span>] hydrogenases was investigated by a combination of first principles and empirical molecular dynamics simulations. Pathways that can be inferred from the X-ray crystal structures of DdH and CpI, i.e., (Glu159→Ser198→Glu156→water460→Cys178→DTMA([<span class="hlt">Fe-Fe</span>](H)) and (Glu282→Ser319→Glu279→water612→Cys299), respectively, were considered. Proton transfer from Cys178 to DTMA in the [<span class="hlt">Fe-Fe</span>](H) sub-cluster in DdH was readily observed in our results, specifically when [<span class="hlt">Fe-Fe</span>](H) was in the reduced state ([<span class="hlt">Fe(I)-Fe</span>(I)]) or in the mixed valence state for the protonated distal iron <span class="hlt">Fe</span>(d) ([<span class="hlt">Fe(I)-Fe</span>(II)-H(-)](H)). A concerted mechanism is proposed, where proton transfer in DdH from Glu159 to Glu156 via Ser198 and Glu156 to Cys178 via water460 readily occurred, as well as from Glu282 to Glu279 via Ser319 and Glu279 to Cys299 via water612 in CpI. The theoretical prediction of the proton transfer characteristics is consistent with the assumed biocatalytic mechanism of the [<span class="hlt">Fe-Fe</span>] hydrogenases in which the proton binds at <span class="hlt">Fe</span>(d), providing confirmation that has not been explored so far. The computational results were qualitatively <span class="hlt">validated</span> by the agreement with experimental hydrogen production activity data for mutated CpI enzymes, relative to the wild-type protein. Finally, the insight provided by the simulations, combined, in part, with experimental <span class="hlt">validation</span>, are important for establishing an approach in future exploration of proton transfer to the active site in this class of enzymes, and possibly also for biomimetic analogs. Published by Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/876739','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/876739"><span>Groundwater <span class="hlt">Model</span> <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ahmed E. Hassan</p> <p>2006-01-24</p> <p><span class="hlt">Models</span> have an inherent uncertainty. The difficulty in fully characterizing the subsurface environment makes uncertainty an integral component of groundwater flow and transport <span class="hlt">models</span>, which dictates the need for continuous monitoring and improvement. Building and sustaining confidence in closure decisions and monitoring networks based on <span class="hlt">models</span> of subsurface conditions require developing confidence in the <span class="hlt">models</span> through an iterative process. The definition of <span class="hlt">model</span> <span class="hlt">validation</span> is postulated as a confidence building and long-term iterative process (Hassan, 2004a). <span class="hlt">Model</span> <span class="hlt">validation</span> should be viewed as a process not an end result. Following Hassan (2004b), an approach is proposed for the <span class="hlt">validation</span> process ofmore » stochastic groundwater <span class="hlt">models</span>. The approach is briefly summarized herein and detailed analyses of acceptance criteria for stochastic realizations and of using <span class="hlt">validation</span> data to reduce input parameter uncertainty are presented and applied to two case studies. During the <span class="hlt">validation</span> process for stochastic <span class="hlt">models</span>, a question arises as to the sufficiency of the number of acceptable <span class="hlt">model</span> realizations (in terms of conformity with <span class="hlt">validation</span> data). Using a hierarchical approach to make this determination is proposed. This approach is based on computing five measures or metrics and following a decision tree to determine if a sufficient number of realizations attain satisfactory scores regarding how they represent the field data used for calibration (old) and used for <span class="hlt">validation</span> (new). The first two of these measures are applied to hypothetical scenarios using the first case study and assuming field data consistent with the <span class="hlt">model</span> or significantly different from the <span class="hlt">model</span> results. In both cases it is shown how the two measures would lead to the appropriate decision about the <span class="hlt">model</span> performance. Standard statistical tests are used to evaluate these measures with the results indicating they are appropriate measures for evaluating <span class="hlt">model</span> realizations. The use of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AIPC.1511..651B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AIPC.1511..651B"><span>Storage strategies of eddy-current <span class="hlt">FE</span>-BI <span class="hlt">model</span> for GPU implementation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bardel, Charles; Lei, Naiguang; Udpa, Lalita</p> <p>2013-01-01</p> <p>In the past few years graphical processing units (GPUs) have shown tremendous improvements in computational throughput over standard CPU architecture. However, this comes at the cost of restructuring the algorithms to meet the strengths and drawbacks of this GPU architecture. A major drawback is the state of limited memory, and hence storage of <span class="hlt">FE</span> stiffness matrices on the GPU is important. In contrast to storage on CPU the GPU storage format has significant influence on the overall performance. This paper presents an investigation of a storage strategy in the implementation of a two-dimensional finite element-boundary integral (<span class="hlt">FE</span>-BI) <span class="hlt">model</span> for Eddy current NDE applications, on GPU architecture. Specifically, the high dimensional matrices are manipulated by examining the matrix structure and optimally splitting into structurally independent component matrices for efficient storage and retrieval of each component. Results obtained using the proposed approach are compared to those of conventional CPU implementation for <span class="hlt">validating</span> the method.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_2 --> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2025642','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2025642"><span>Atomic Resolution <span class="hlt">Modeling</span> of the Ferredoxin:[<span class="hlt">FeFe</span>] Hydrogenase Complex from Chlamydomonas reinhardtii</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chang, Christopher H.; King, Paul W.; Ghirardi, Maria L.; Kim, Kwiseon</p> <p>2007-01-01</p> <p>The [<span class="hlt">FeFe</span>] hydrogenases HydA1 and HydA2 in the green alga Chlamydomonas reinhardtii catalyze the final reaction in a remarkable metabolic pathway allowing this photosynthetic organism to produce H2 from water in the chloroplast. A [2<span class="hlt">Fe</span>-2S] ferredoxin is a critical branch point in electron flow from Photosystem I toward a variety of metabolic fates, including proton reduction by hydrogenases. To better understand the binding determinants involved in ferredoxin:hydrogenase interactions, we have <span class="hlt">modeled</span> Chlamydomonas PetF1 and HydA2 based on amino-acid sequence homology, and produced two promising electron-transfer <span class="hlt">model</span> complexes by computational docking. To characterize these <span class="hlt">models</span>, quantitative free energy calculations at atomic resolution were carried out, and detailed analysis of the interprotein interactions undertaken. The protein complex <span class="hlt">model</span> we propose for ferredoxin:HydA2 interaction is energetically favored over the alternative candidate by 20 kcal/mol. This proposed <span class="hlt">model</span> of the electron-transfer complex between PetF1 and HydA2 permits a more detailed view of the molecular events leading up to H2 evolution, and suggests potential mutagenic strategies to modulate electron flow to HydA2. PMID:17660315</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17660315','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17660315"><span>Atomic resolution <span class="hlt">modeling</span> of the ferredoxin:[<span class="hlt">FeFe</span>] hydrogenase complex from Chlamydomonas reinhardtii.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chang, Christopher H; King, Paul W; Ghirardi, Maria L; Kim, Kwiseon</p> <p>2007-11-01</p> <p>The [<span class="hlt">FeFe</span>] hydrogenases HydA1 and HydA2 in the green alga Chlamydomonas reinhardtii catalyze the final reaction in a remarkable metabolic pathway allowing this photosynthetic organism to produce H(2) from water in the chloroplast. A [2<span class="hlt">Fe</span>-2S] ferredoxin is a critical branch point in electron flow from Photosystem I toward a variety of metabolic fates, including proton reduction by hydrogenases. To better understand the binding determinants involved in ferredoxin:hydrogenase interactions, we have <span class="hlt">modeled</span> Chlamydomonas PetF1 and HydA2 based on amino-acid sequence homology, and produced two promising electron-transfer <span class="hlt">model</span> complexes by computational docking. To characterize these <span class="hlt">models</span>, quantitative free energy calculations at atomic resolution were carried out, and detailed analysis of the interprotein interactions undertaken. The protein complex <span class="hlt">model</span> we propose for ferredoxin:HydA2 interaction is energetically favored over the alternative candidate by 20 kcal/mol. This proposed <span class="hlt">model</span> of the electron-transfer complex between PetF1 and HydA2 permits a more detailed view of the molecular events leading up to H(2) evolution, and suggests potential mutagenic strategies to modulate electron flow to HydA2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23662901','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23662901"><span>Carbonate-mediated <span class="hlt">Fe</span>(II) oxidation in the air-cathode fuel cell: a kinetic <span class="hlt">model</span> in terms of <span class="hlt">Fe</span>(II) speciation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Song, Wei; Zhai, Lin-Feng; Cui, Yu-Zhi; Sun, Min; Jiang, Yuan</p> <p>2013-06-06</p> <p>Due to the high redox activity of <span class="hlt">Fe</span>(II) and its abundance in natural waters, the electro-oxidation of <span class="hlt">Fe</span>(II) can be found in many air-cathode fuel cell systems, such as acid mine drainage fuel cells and sediment microbial fuel cells. To deeply understand these iron-related systems, it is essential to elucidate the kinetics and mechanisms involved in the electro-oxidation of <span class="hlt">Fe</span>(II). This work aims to develop a kinetic <span class="hlt">model</span> that adequately describes the electro-oxidation process of <span class="hlt">Fe</span>(II) in air-cathode fuel cells. The speciation of <span class="hlt">Fe</span>(II) is incorporated into the <span class="hlt">model</span>, and contributions of individual <span class="hlt">Fe</span>(II) species to the overall <span class="hlt">Fe</span>(II) oxidation rate are quantitatively evaluated. The results show that the kinetic <span class="hlt">model</span> can accurately predict the electro-oxidation rate of <span class="hlt">Fe</span>(II) in air-cathode fuel cells. <span class="hlt">Fe</span>CO3, <span class="hlt">Fe</span>(OH)2, and <span class="hlt">Fe</span>(CO3)2(2-) are the most important species determining the electro-oxidation kinetics of <span class="hlt">Fe</span>(II). The <span class="hlt">Fe</span>(II) oxidation rate is primarily controlled by the oxidation of <span class="hlt">Fe</span>CO3 species at low pH, whereas at high pH <span class="hlt">Fe</span>(OH)2 and <span class="hlt">Fe</span>(CO3)2(2-) are the dominant species. Solution pH, carbonate concentration, and solution salinity are able to influence the electro-oxidation kinetics of <span class="hlt">Fe</span>(II) through changing both distribution and kinetic activity of <span class="hlt">Fe</span>(II) species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/894170','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/894170"><span><span class="hlt">Model</span> <span class="hlt">Validation</span> Status Review</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>E.L. Hardin</p> <p></p> <p>The primary objective for the <span class="hlt">Model</span> <span class="hlt">Validation</span> Status Review was to perform a one-time evaluation of <span class="hlt">model</span> <span class="hlt">validation</span> associated with the analysis/<span class="hlt">model</span> reports (AMRs) containing <span class="hlt">model</span> input to total-system performance assessment (TSPA) for the Yucca Mountain site recommendation (SR). This review was performed in response to Corrective Action Request BSC-01-C-01 (Clark 2001, Krisha 2001) pursuant to Quality Assurance review findings of an adverse trend in <span class="hlt">model</span> <span class="hlt">validation</span> deficiency. The review findings in this report provide the following information which defines the extent of <span class="hlt">model</span> <span class="hlt">validation</span> deficiency and the corrective action needed: (1) AMRs that contain or support <span class="hlt">models</span> are identified,more » and conversely, for each <span class="hlt">model</span> the supporting documentation is identified. (2) The use for each <span class="hlt">model</span> is determined based on whether the output is used directly for TSPA-SR, or for screening (exclusion) of features, events, and processes (FEPs), and the nature of the <span class="hlt">model</span> output. (3) Two approaches are used to evaluate the extent to which the <span class="hlt">validation</span> for each <span class="hlt">model</span> is compliant with AP-3.10Q (Analyses and <span class="hlt">Models</span>). The approaches differ in regard to whether <span class="hlt">model</span> <span class="hlt">validation</span> is achieved within individual AMRs as originally intended, or whether <span class="hlt">model</span> <span class="hlt">validation</span> could be readily achieved by incorporating information from other sources. (4) Recommendations are presented for changes to the AMRs, and additional <span class="hlt">model</span> development activities or data collection, that will remedy <span class="hlt">model</span> <span class="hlt">validation</span> review findings, in support of licensing activities. The <span class="hlt">Model</span> <span class="hlt">Validation</span> Status Review emphasized those AMRs that support TSPA-SR (CRWMS M&O 2000bl and 2000bm). A series of workshops and teleconferences was held to discuss and integrate the review findings. The review encompassed 125 AMRs (Table 1) plus certain other supporting documents and data needed to assess <span class="hlt">model</span> <span class="hlt">validity</span>. The AMRs were grouped in 21 <span class="hlt">model</span> areas representing the <span class="hlt">modeling</span> of processes affecting the natural</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JQSRT.211...78R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JQSRT.211...78R"><span>Linearized Flux Evolution (Li<span class="hlt">FE</span>): A technique for rapidly adapting fluxes from full-physics radiative transfer <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Robinson, Tyler D.; Crisp, David</p> <p>2018-05-01</p> <p>Solar and thermal radiation are critical aspects of planetary climate, with gradients in radiative energy fluxes driving heating and cooling. Climate <span class="hlt">models</span> require that radiative transfer tools be versatile, computationally efficient, and accurate. Here, we describe a technique that uses an accurate full-physics radiative transfer <span class="hlt">model</span> to generate a set of atmospheric radiative quantities which can be used to linearly adapt radiative flux profiles to changes in the atmospheric and surface state-the Linearized Flux Evolution (Li<span class="hlt">FE</span>) approach. These radiative quantities describe how each <span class="hlt">model</span> layer in a plane-parallel atmosphere reflects and transmits light, as well as how the layer generates diffuse radiation by thermal emission and by scattering light from the direct solar beam. By computing derivatives of these layer radiative properties with respect to dynamic elements of the atmospheric state, we can then efficiently adapt the flux profiles computed by the full-physics <span class="hlt">model</span> to new atmospheric states. We <span class="hlt">validate</span> the Li<span class="hlt">FE</span> approach, and then apply this approach to Mars, Earth, and Venus, demonstrating the information contained in the layer radiative properties and their derivatives, as well as how the Li<span class="hlt">FE</span> approach can be used to determine the thermal structure of radiative and radiative-convective equilibrium states in one-dimensional atmospheric <span class="hlt">models</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptLT..98..363L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptLT..98..363L"><span>A procedure for calibration and <span class="hlt">validation</span> of <span class="hlt">FE</span> <span class="hlt">modelling</span> of laser-assisted metal to polymer direct joining</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lambiase, F.; Genna, S.; Kant, R.</p> <p>2018-01-01</p> <p>The quality of the joints produced by means of Laser-Assisted Metal to Polymer direct joining (LAMP) is strongly influenced by the temperature field produced during the laser treatment. The main phenomena including the adhesion of the plastic to the metal sheet and the development of bubbles (on the plastic surface) depend on the temperature reached by the polymer at the interface. Such a temperature should be higher than the softening temperature, but lower than the degradation temperature of the polymer. However, the temperature distribution is difficult to be measured by experimental tests since the most polymers (which are transparent to the laser radiation) are often opaque to the infrared wavelength. Thus, infrared analysis involving pyrometers and infrared camera is not suitable for this purpose. On the other hand, thermocouples are difficult to be placed at the interface without influencing the temperature conditions. In this paper, an integrated approach involving both experimental measurements and a Finite Element (<span class="hlt">FE</span>) <span class="hlt">model</span> were used to perform such an analysis. LAMP of Polycarbonate and AISI304 stainless steel was performed by means of high power diode laser and the main process parameters i.e. laser power and scanning speed were varied. Comparing the experimental measurements and the <span class="hlt">FE</span> <span class="hlt">model</span> prediction of the thermal field, a good correspondence was achieved proving the suitability of the developed <span class="hlt">model</span> and the proposed calibration procedure to be ready used for process design and optimization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24786914','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24786914"><span>Development and <span class="hlt">validation</span> of a computational <span class="hlt">model</span> of the knee joint for the evaluation of surgical treatments for osteoarthritis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mootanah, R; Imhauser, C W; Reisse, F; Carpanen, D; Walker, R W; Koff, M F; Lenhoff, M W; Rozbruch, S R; Fragomen, A T; Dewan, Z; Kirane, Y M; Cheah, K; Dowell, J K; Hillstrom, H J</p> <p>2014-01-01</p> <p>A three-dimensional (3D) knee joint computational <span class="hlt">model</span> was developed and <span class="hlt">validated</span> to predict knee joint contact forces and pressures for different degrees of malalignment. A 3D computational knee <span class="hlt">model</span> was created from high-resolution radiological images to emulate passive sagittal rotation (full-extension to 65°-flexion) and weight acceptance. A cadaveric knee mounted on a six-degree-of-freedom robot was subjected to matching boundary and loading conditions. A ligament-tuning process minimised kinematic differences between the robotically loaded cadaver specimen and the finite element (<span class="hlt">FE</span>) <span class="hlt">model</span>. The <span class="hlt">model</span> was <span class="hlt">validated</span> by measured intra-articular force and pressure measurements. Percent full scale error between <span class="hlt">FE</span>-predicted and in vitro-measured values in the medial and lateral compartments were 6.67% and 5.94%, respectively, for normalised peak pressure values, and 7.56% and 4.48%, respectively, for normalised force values. The knee <span class="hlt">model</span> can accurately predict normalised intra-articular pressure and forces for different loading conditions and could be further developed for subject-specific surgical planning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008ApJ...675...83B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008ApJ...675...83B"><span><span class="hlt">Modeling</span> <span class="hlt">Fe</span> II Emission and Revised <span class="hlt">Fe</span> II (UV) Empirical Templates for the Seyfert 1 Galaxy I Zw 1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bruhweiler, F.; Verner, E.</p> <p>2008-03-01</p> <p>We use the narrow-lined broad-line region (BLR) of the Seyfert 1 galaxy, I Zw 1, as a laboratory for <span class="hlt">modeling</span> the ultraviolet (UV) <span class="hlt">Fe</span> II 2100-3050 Å emission complex. We calculate a grid of <span class="hlt">Fe</span> II emission spectra representative of BLR clouds and compare them with the observed I Zw 1 spectrum. Our predicted spectrum for log [nH/(cm -3) ] = 11.0, log [ΦH/(cm -2 s-1) ] = 20.5, and ξ/(1 km s-1) = 20, using Cloudy and an 830 level <span class="hlt">model</span> atom for <span class="hlt">Fe</span> II with energies up to 14.06 eV, gives a better fit to the UV <span class="hlt">Fe</span> II emission than <span class="hlt">models</span> with fewer levels. Our analysis indicates (1) the observed UV <span class="hlt">Fe</span> II emission must be corrected for an underlying <span class="hlt">Fe</span> II pseudocontinuum; (2) <span class="hlt">Fe</span> II emission peaks can be misidentified as that of other ions in active galactic nuclei (AGNs) with narrow-lined BLRs possibly affecting deduced physical parameters; (3) the shape of 4200-4700 Å <span class="hlt">Fe</span> II emission in I Zw 1 and other AGNs is a relative indicator of narrow-line region (NLR) and BLR <span class="hlt">Fe</span> II emission; (4) predicted ratios of Lyα, C III], and <span class="hlt">Fe</span> II emission relative to Mg II λ2800 agree with extinction corrected observed I Zw 1 fluxes, except for C IV λ1549 (5) the sensitivity of <span class="hlt">Fe</span> II emission strength to microturbulence ξ casts doubt on existing relative <span class="hlt">Fe</span>/Mg abundances derived from <span class="hlt">Fe</span> II (UV)/Mg II flux ratios. Our calculated <span class="hlt">Fe</span> II emission spectra, suitable for BLRs in AGNs, are available at http://iacs.cua.edu/people/verner/<span class="hlt">Fe</span>II. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 05-26555.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015HTMP...34....1F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015HTMP...34....1F"><span>A Simple Kinetic <span class="hlt">Model</span> for the Growth of <span class="hlt">Fe</span>2B Layers on AISI 1026 Steel During the Powder-pack Boriding</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flores-Rentería, M. A.; Ortiz-Domínguez, M.; Keddam, M.; Damián-Mejía, O.; Elias-Espinosa, M.; Flores-González, M. A.; Medina-Moreno, S. A.; Cruz-Avilés, A.; Villanueva-Ibañez, M.</p> <p>2015-02-01</p> <p>This work focused on the determination of boron diffusion coefficient through the <span class="hlt">Fe</span>2B layers on AISI 1026 steel using a mathematical <span class="hlt">model</span>. The suggested <span class="hlt">model</span> solves the mass balance equation at the (<span class="hlt">Fe</span>2B/substrate) interface. This thermochemical treatment was carried out in the temperature range of 1123-1273 K for a treatment time ranging from 2 to 8 h. The generated boride layers were characterized by different experimental techniques such as light optical microscopy, scanning electron microscopy, XRD analysis and the Daimler-Benz Rockwell-C indentation technique. As a result, the boron activation energy for AISI 1026 steel was estimated as 178.4 kJ/mol. Furthermore, this kinetic <span class="hlt">model</span> was <span class="hlt">validated</span> by comparing the experimental <span class="hlt">Fe</span>2B layer thickness with the predicted one at a temperature of 1253 K for 5 h of treatment. A contour diagram relating the layer thickness to the boriding parameters was proposed to be used in practical applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RJPCA..91.2593L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RJPCA..91.2593L"><span>3D Computer <span class="hlt">Models</span> of T- x- y Diagrams, Forming the <span class="hlt">Fe-Ni-Co-Fe</span>S-NiS-CoS Subsystem</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lutsyk, V. I.; Vorob'eva, V. P.</p> <p>2017-12-01</p> <p>3D computer <span class="hlt">models</span> of <span class="hlt">Fe</span>-Ni-Co, <span class="hlt">Fe-Ni-Fe</span>S-NiS, <span class="hlt">Fe-Co-Fe</span>S-CoS, Ni-Co-NiS-CoS T- x- y diagrams have been designed. The geometric structure (35 surfaces, two-phase surface of the reaction type change, 17 phase regions) of the <span class="hlt">Fe-Ni-Fe</span>S-NiS T- x- y diagram is investigated in detail. The liquidus hypersurfaces prediction of the <span class="hlt">Fe-Ni-Co-Fe</span>S-NiS-CoS subsystem is represented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPC.1457..361R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPC.1457..361R"><span>Quantitative <span class="hlt">validation</span> of an air-coupled ultrasonic probe <span class="hlt">model</span> by Interferometric laser tomography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Revel, G. M.; Pandarese, G.; Cavuto, A.</p> <p>2012-06-01</p> <p>The present paper describes the quantitative <span class="hlt">validation</span> of a finite element (<span class="hlt">FE</span>) <span class="hlt">model</span> of the ultrasound beam generated by an air coupled non-contact ultrasound transducer. The <span class="hlt">model</span> boundary conditions are given by vibration velocities measured by laser vibrometry on the probe membrane. The proposed <span class="hlt">validation</span> method is based on the comparison between the simulated 3D pressure field and the pressure data measured with interferometric laser tomography technique. The <span class="hlt">model</span> details and the experimental techniques are described in paper. The analysis of results shows the effectiveness of the proposed approach and the possibility to quantitatively assess and predict the generated acoustic pressure field, with maximum discrepancies in the order of 20% due to uncertainty effects. This step is important for determining in complex problems the real applicability of air-coupled probes and for the simulation of the whole inspection procedure, also when the component is designed, so as to virtually verify its inspectability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3232896','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3232896"><span>Ab Initio Structural <span class="hlt">Modeling</span> of and Experimental <span class="hlt">Validation</span> for Chlamydia trachomatis Protein CT296 Reveal Structural Similarity to <span class="hlt">Fe</span>(II) 2-Oxoglutarate-Dependent Enzymes▿</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kemege, Kyle E.; Hickey, John M.; Lovell, Scott; Battaile, Kevin P.; Zhang, Yang; Hefty, P. Scott</p> <p>2011-01-01</p> <p>Chlamydia trachomatis is a medically important pathogen that encodes a relatively high percentage of proteins with unknown function. The three-dimensional structure of a protein can be very informative regarding the protein's functional characteristics; however, determining protein structures experimentally can be very challenging. Computational methods that <span class="hlt">model</span> protein structures with sufficient accuracy to facilitate functional studies have had notable successes. To evaluate the accuracy and potential impact of computational protein structure <span class="hlt">modeling</span> of hypothetical proteins encoded by Chlamydia, a successful computational method termed I-TASSER was utilized to <span class="hlt">model</span> the three-dimensional structure of a hypothetical protein encoded by open reading frame (ORF) CT296. CT296 has been reported to exhibit functional properties of a divalent cation transcription repressor (DcrA), with similarity to the Escherichia coli iron-responsive transcriptional repressor, Fur. Unexpectedly, the I-TASSER <span class="hlt">model</span> of CT296 exhibited no structural similarity to any DNA-interacting proteins or motifs. To <span class="hlt">validate</span> the I-TASSER-generated <span class="hlt">model</span>, the structure of CT296 was solved experimentally using X-ray crystallography. Impressively, the ab initio I-TASSER-generated <span class="hlt">model</span> closely matched (2.72-Å Cα root mean square deviation [RMSD]) the high-resolution (1.8-Å) crystal structure of CT296. <span class="hlt">Modeled</span> and experimentally determined structures of CT296 share structural characteristics of non-heme <span class="hlt">Fe</span>(II) 2-oxoglutarate-dependent enzymes, although key enzymatic residues are not conserved, suggesting a unique biochemical process is likely associated with CT296 function. Additionally, functional analyses did not support prior reports that CT296 has properties shared with divalent cation repressors such as Fur. PMID:21965559</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NatCh..10..555R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NatCh..10..555R"><span>A [4<span class="hlt">Fe</span>-4S]-<span class="hlt">Fe</span>(CO)(CN)-l-cysteine intermediate is the first organometallic precursor in [<span class="hlt">FeFe</span>] hydrogenase H-cluster bioassembly</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rao, Guodong; Tao, Lizhi; Suess, Daniel L. M.; Britt, R. David</p> <p>2018-05-01</p> <p>Biosynthesis of the [<span class="hlt">FeFe</span>] hydrogenase active site (the 'H-cluster') requires the interplay of multiple proteins and small molecules. Among them, the radical S-adenosylmethionine enzyme HydG, a tyrosine lyase, has been proposed to generate a complex that contains an <span class="hlt">Fe</span>(CO)2(CN) moiety that is eventually incorporated into the H-cluster. Here we describe the characterization of an intermediate in the HydG reaction: a [4<span class="hlt">Fe</span>-4S][(Cys)<span class="hlt">Fe</span>(CO)(CN)] species, 'Complex A', in which a CO, a CN- and a cysteine (Cys) molecule bind to the unique 'dangler' <span class="hlt">Fe</span> site of the auxiliary [5<span class="hlt">Fe</span>-4S] cluster of HydG. The identification of this intermediate—the first organometallic precursor to the H-cluster—<span class="hlt">validates</span> the previously hypothesized HydG reaction cycle and provides a basis for elucidating the biosynthetic origin of other moieties of the H-cluster.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25422384','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25422384"><span>External <span class="hlt">validation</span> of blood eosinophils, <span class="hlt">FE</span>(NO) and serum periostin as surrogates for sputum eosinophils in asthma.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wagener, A H; de Nijs, S B; Lutter, R; Sousa, A R; Weersink, E J M; Bel, E H; Sterk, P J</p> <p>2015-02-01</p> <p>Monitoring sputum eosinophils in asthma predicts exacerbations and improves management of asthma. Thus far, blood eosinophils and <span class="hlt">FE</span>(NO) show contradictory results in predicting eosinophilic airway inflammation. More recently, serum periostin was proposed as a novel biomarker for eosinophilic inflammation. Quantifying the mutual relationships of blood eosinophils, <span class="hlt">FE</span>(NO), and serum periostin with sputum eosinophils by external <span class="hlt">validation</span> in two independent cohorts across various severities of asthma. The first cohort consisted of 110 patients with mild to moderate asthma (external <span class="hlt">validation</span> cohort). The replication cohort consisted of 37 patients with moderate to severe asthma. Both cohorts were evaluated cross-sectionally. Sputum was induced for the assessment of eosinophils. In parallel, blood eosinophil counts, serum periostin concentrations and FENO were assessed. The diagnostic accuracy of these markers to identify eosinophilic asthma (sputum eosinophils ≥3%) was calculated using receiver operating characteristics area under the curve (ROC AUC). In the external <span class="hlt">validation</span> cohort, ROC AUC for blood eosinophils was 89% (p<0.001) and for <span class="hlt">FE</span>(NO) level 78% (p<0.001) to detect sputum eosinophilia ≥3%. Serum periostin was not able to distinguish eosinophilic from non-eosinophilic airway inflammation (ROC AUC=55%, p=0.44). When combining these three variables, no improvement was seen. The diagnostic value of blood eosinophils was confirmed in the replication cohort (ROC AUC 85%, p<0.001). In patients with mild to moderate asthma, as well as patients with more severe asthma, blood eosinophils had the highest accuracy in the identification of sputum eosinophilia in asthma. The use of blood eosinophils can facilitate individualised treatment and management of asthma. NTR1846 and NTR2364. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..140a2030A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..140a2030A"><span>Assessment of kinetic <span class="hlt">models</span> on <span class="hlt">Fe</span> adsorption in groundwater using high-quality limestone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akbar, N. A.; Kamil, N. A. F. Mohd; Zin, N. S. Md; Adlan, M. N.; Aziz, H. A.</p> <p>2018-04-01</p> <p>During the groundwater pumping process, dissolved <span class="hlt">Fe</span>2+ is oxidized into <span class="hlt">Fe</span>3+ and produce rust-coloured iron mineral. Adsorption kinetic <span class="hlt">models</span> are used to evaluate the performance of limestone adsorbent and describe the mechanism of adsorption and the diffusion processes of <span class="hlt">Fe</span> adsorption in groundwater. This work presents the best kinetic <span class="hlt">model</span> of <span class="hlt">Fe</span> adsorption, which was chosen based on a higher value of coefficient correlation, R2. A batch adsorption experiment was conducted for various contact times ranging from 0 to 135 minutes. From the results of the batch study, three kinetic <span class="hlt">models</span> were analyzed for <span class="hlt">Fe</span> removal onto limestone sorbent, including the pseudo-first order (PFO), pseudo-second order (PSO) and intra-particle diffusion (IPD) <span class="hlt">models</span>. Results show that the adsorption kinetic <span class="hlt">models</span> follow the sequence: PSO > PFO > IPD, where the values of R2 are 0.997 > 0.919 > 0.918. A high value of R2 (0.997) reveals better fitted experimental data. Furthermore, the value of qe cal in the PSO kinetic <span class="hlt">model</span> is very near to qe exp rather than that in other <span class="hlt">models</span>. This finding therefore suggests that the PSO kinetic <span class="hlt">model</span> has the good fitted with the experimental data which involved chemisorption process of divalent <span class="hlt">Fe</span> removal in groundwater solution. Thus, limestone adsorbent media found to be an alternative and effective treatment of <span class="hlt">Fe</span> removal from groundwater.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1313657-power-plant-model-validation-tool','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1313657-power-plant-model-validation-tool"><span>Power Plant <span class="hlt">Model</span> <span class="hlt">Validation</span> Tool</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p></p> <p></p> <p>The PPMV is used to <span class="hlt">validate</span> generator <span class="hlt">model</span> using disturbance recordings. The PPMV tool contains a collection of power plant <span class="hlt">models</span> and <span class="hlt">model</span> <span class="hlt">validation</span> studies, as well as disturbance recordings from a number of historic grid events. The user can import data from a new disturbance into the database, which converts PMU and SCADA data into GE PSLF format, and then run the tool to <span class="hlt">validate</span> (or invalidate) the <span class="hlt">model</span> for a specific power plant against its actual performance. The PNNL PPMV tool enables the automation of the process of power plant <span class="hlt">model</span> <span class="hlt">validation</span> using disturbance recordings. The tool usesmore » PMU and SCADA measurements as input information. The tool automatically adjusts all required EPCL scripts and interacts with GE PSLF in the batch mode. The main tool features includes: The tool interacts with GE PSLF; The tool uses GE PSLF Play-In Function for generator <span class="hlt">model</span> <span class="hlt">validation</span>; Database of projects (<span class="hlt">model</span> <span class="hlt">validation</span> studies); Database of the historic events; Database of the power plant; The tool has advanced visualization capabilities; and The tool automatically generates reports« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/949065-modeling-reaction-fe-atoms-ccl4','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/949065-modeling-reaction-fe-atoms-ccl4"><span><span class="hlt">Modeling</span> the Reaction of <span class="hlt">Fe</span> Atoms with CCl4</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Camaioni, Donald M.; Ginovska, Bojana; Dupuis, Michel</p> <p>2009-01-05</p> <p>The reaction of zero-valent iron with carbon tetrachloride (CCl4) in gas phase was studied using density functional theory. Temperature programmed desorption experiments over a range of <span class="hlt">Fe</span> and CCl4 coverages on a <span class="hlt">Fe</span>O(111) surface, demonstrate a rich surface chemistry with several reaction products (C2Cl4, C2Cl6, OCCl2, CO, <span class="hlt">Fe</span>Cl2, <span class="hlt">Fe</span>Cl3) observed. The reactivity of <span class="hlt">Fe</span> and CCl4 was studied under three stoichiometries, one <span class="hlt">Fe</span> with one CCl4, one <span class="hlt">Fe</span> with two CCl4 molecules and two <span class="hlt">Fe</span> with one CCl4, <span class="hlt">modeling</span> the environment of the experimental work. The electronic structure calculations give insight into the reactions leading to the experimentally observed productsmore » and suggest that novel <span class="hlt">Fe</span>-C-Cl containing species are important intermediates in these reactions. The intermediate complexes are formed in highly exothermic reactions, in agreement with the experimentally observed reactivity with the surface at low temperature (30 K). This initial survey of the reactivity of <span class="hlt">Fe</span> with CCl4 identifies some potential reaction pathways that are important in the effort to use <span class="hlt">Fe</span> nano-particles to differentiate harmful pathways that lead to the formation of contaminants like chloroform (CHCl3) from harmless pathways that lead to products such as formate (HCO2-) or carbon oxides in water and soil. The Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JIEIC..98..567G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JIEIC..98..567G"><span><span class="hlt">Modelling</span> the Peak Elongation of Nylon6 and <span class="hlt">Fe</span> Powder Based Composite Wire for FDM Feedstock Filament</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garg, Harish Kumar; Singh, Rupinder</p> <p>2017-10-01</p> <p>In the present work, to increase the application domain of fused deposition <span class="hlt">modelling</span> (FDM) process, Nylon6-<span class="hlt">Fe</span> powder based composite wire has been prepared as feed stock filament. Further for smooth functioning of feed stock filament without any change in the hardware and software of the commercial FDM setup, the mechanical properties of the newly prepared composite wire must be comparable/at par to the existing material i.e. ABS, P-430. So, keeping this in consideration; an effort has been made to <span class="hlt">model</span> the peak elongation of in house developed feedstock filament comprising of Nylon6 and <span class="hlt">Fe</span> powder (prepared on single screw extrusion process) for commercial FDM setup. The input parameters of single screw extruder (namely: barrel temperature, temperature of the die, speed of the screw, speed of the winding machine) and rheological property of material (melt flow index) has been <span class="hlt">modelled</span> with peak elongation as the output by using response surface methodology. For <span class="hlt">validation</span> of <span class="hlt">model</span> the result of peak elongation obtained from the <span class="hlt">model</span> equation the comparison was made with the results of actual experimentation which shows the variation of ±1 % only.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JNuM..489..118F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JNuM..489..118F"><span>Mechanical properties of neutron-irradiated <span class="hlt">model</span> and commercial <span class="hlt">Fe</span>CrAl alloys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Field, Kevin G.; Briggs, Samuel A.; Sridharan, Kumar; Howard, Richard H.; Yamamoto, Yukinori</p> <p>2017-06-01</p> <p>The development and understanding of the mechanical properties of neutron-irradiated <span class="hlt">Fe</span>CrAl alloys is increasingly a critical need as these alloys continue to become more mature for nuclear reactor applications. This study focuses on the mechanical properties of <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys and of a commercial <span class="hlt">Fe</span>CrAl alloy neutron-irradiated to up to 13.8 displacements per atom (dpa) at irradiation temperatures between 320 and 382 °C. Tensile tests were completed at room temperature and at 320 °C, and a subset of fractured tensile specimens was examined by scanning electron microscopy. Results showed typical radiation hardening and embrittlement indicative of high chromium ferritic alloys with strong chromium composition dependencies at lower doses. At and above 7.0 dpa, the mechanical properties saturated for both the commercial and <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys, although brittle cleavage fracture was observed at the highest dose in the <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloy with the highest chromium content (18 wt %). The results suggest the composition and microstructure of <span class="hlt">Fe</span>CrAl alloys plays a critical role in the mechanical response of <span class="hlt">Fe</span>CrAl alloys irradiated near temperatures relevant to light water reactors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUSM.V44A..03D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUSM.V44A..03D"><span><span class="hlt">Modeling</span> Equilibrium <span class="hlt">Fe</span> Isotope Fractionation in <span class="hlt">Fe</span>-Organic Complexes: Implications for the use of <span class="hlt">Fe</span> Isotopes as a Biomarker and Trends Based on the Properties of Bound Ligands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Domagal-Goldman, S.; Kubicki, J. D.</p> <p>2006-05-01</p> <p><span class="hlt">Fe</span> Isotopes have been proposed as a useful tracer of biological and geochemical processes. Key to understanding the effects these various processes have on <span class="hlt">Fe</span> isotopes is accurate <span class="hlt">modeling</span> of the reactions responsible for the isotope fractionations. In this study, we examined the theoretical basis for the claims that <span class="hlt">Fe</span> isotopes can be used as a biomarker. This was done by using molecular orbital/density functional theory (MO/DFT) calculations to predict the equilibrium fractionation of <span class="hlt">Fe</span> isotopes due to changes in the redox state and the bonding environment of <span class="hlt">Fe</span>. Specifically, we predicted vibrational frequencies for iron desferrioxamine (<span class="hlt">Fe</span>-DFOB), iron triscatechol (<span class="hlt">Fe</span>(cat)3), iron trisoxalate (<span class="hlt">Fe</span>(ox)3), and hexaaquo iron (<span class="hlt">Fe</span>(H2O)6) for complexes containing both ferrous (<span class="hlt">Fe</span>2+) and ferric (<span class="hlt">Fe</span>3+) iron. Using these vibrational frequencies, we then predicted fractionation factors between these six complexes. The predicted fractionation factors resulting from changes in the redox state of <span class="hlt">Fe</span> fell in the range 2.5- 3.5‰. The fractionation factors resulting from changes in the bonding environment of <span class="hlt">Fe</span> ranged from 0.2 to 1.4‰. These results indicate that changes in the bonding strength of <span class="hlt">Fe</span> ligands are less important to <span class="hlt">Fe</span> isotope fractionation processes than are changes to the redox state of <span class="hlt">Fe</span>. The implications for use of <span class="hlt">Fe</span> as a tracer of biological processes is clear: abiological redox changes must be ruled out in a sample before <span class="hlt">Fe</span> isotopes are considered as a potential biomarker. Furthermore, the use of <span class="hlt">Fe</span> isotopes to measure the redox state of the Earths surface environment through time is supported by this work, since changes in the redox state of <span class="hlt">Fe</span> appear to be the more important driver of isotopic fractionations. In addition to the large differences between redox-driven fractionations and ligand-driven fractionations, we will also show general trends in the demand for heavy <span class="hlt">Fe</span> isotopes as a function of properties of the bound ligand. This will help the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MMTB...47.1187T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MMTB...47.1187T"><span>A Structural Molar Volume <span class="hlt">Model</span> for Oxide Melts Part III: <span class="hlt">Fe</span> Oxide-Containing Melts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thibodeau, Eric; Gheribi, Aimen E.; Jung, In-Ho</p> <p>2016-04-01</p> <p>As part III of this series, the <span class="hlt">model</span> is extended to iron oxide-containing melts. All available experimental data in the <span class="hlt">FeO-Fe</span>2O3-Na2O-K2O-MgO-CaO-MnO-Al2O3-SiO2 system were critically evaluated based on the experimental condition. The variations of <span class="hlt">Fe</span>O and <span class="hlt">Fe</span>2O3 in the melts were taken into account by using FactSage to calculate the <span class="hlt">Fe</span>2+/<span class="hlt">Fe</span>3+ distribution. The molar volume <span class="hlt">model</span> with unary and binary <span class="hlt">model</span> parameters can be used to predict the molar volume of the molten oxide of the Li2O-Na2O-K2O-MgO-CaO-MnO-PbO-<span class="hlt">FeO-Fe</span>2O3-Al2O3-SiO2 system in the entire range of compositions, temperatures, and oxygen partial pressures from <span class="hlt">Fe</span> saturation to 1 atm pressure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1034930-ab-initio-structural-modeling-experimental-validation-chlamydia-trachomatis-protein-ct296-reveal-structural-similarity-fe-ii-oxoglutarate-dependent-enzymes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1034930-ab-initio-structural-modeling-experimental-validation-chlamydia-trachomatis-protein-ct296-reveal-structural-similarity-fe-ii-oxoglutarate-dependent-enzymes"><span>Ab initio structural <span class="hlt">modeling</span> of and experimental <span class="hlt">validation</span> for Chlamydia trachomatis protein CT296 reveal structural similarity to <span class="hlt">Fe</span>(II) 2-oxoglutarate-dependent enzymes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kemege, Kyle E.; Hickey, John M.; Lovell, Scott</p> <p>2012-02-13</p> <p>Chlamydia trachomatis is a medically important pathogen that encodes a relatively high percentage of proteins with unknown function. The three-dimensional structure of a protein can be very informative regarding the protein's functional characteristics; however, determining protein structures experimentally can be very challenging. Computational methods that <span class="hlt">model</span> protein structures with sufficient accuracy to facilitate functional studies have had notable successes. To evaluate the accuracy and potential impact of computational protein structure <span class="hlt">modeling</span> of hypothetical proteins encoded by Chlamydia, a successful computational method termed I-TASSER was utilized to <span class="hlt">model</span> the three-dimensional structure of a hypothetical protein encoded by open reading frame (ORF)more » CT296. CT296 has been reported to exhibit functional properties of a divalent cation transcription repressor (DcrA), with similarity to the Escherichia coli iron-responsive transcriptional repressor, Fur. Unexpectedly, the I-TASSER <span class="hlt">model</span> of CT296 exhibited no structural similarity to any DNA-interacting proteins or motifs. To <span class="hlt">validate</span> the I-TASSER-generated <span class="hlt">model</span>, the structure of CT296 was solved experimentally using X-ray crystallography. Impressively, the ab initio I-TASSER-generated <span class="hlt">model</span> closely matched (2.72-{angstrom} C{alpha} root mean square deviation [RMSD]) the high-resolution (1.8-{angstrom}) crystal structure of CT296. <span class="hlt">Modeled</span> and experimentally determined structures of CT296 share structural characteristics of non-heme <span class="hlt">Fe</span>(II) 2-oxoglutarate-dependent enzymes, although key enzymatic residues are not conserved, suggesting a unique biochemical process is likely associated with CT296 function. Additionally, functional analyses did not support prior reports that CT296 has properties shared with divalent cation repressors such as Fur.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27393912','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27393912"><span>Development and <span class="hlt">validation</span> of a generic finite element vehicle buck <span class="hlt">model</span> for the analysis of driver rib fractures in real life nearside oblique frontal crashes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Iraeus, Johan; Lindquist, Mats</p> <p>2016-10-01</p> <p>Frontal crashes still account for approximately half of all fatalities in passenger cars, despite several decades of crash-related research. For serious injuries in this crash mode, several authors have listed the thorax as the most important. Computer simulation provides an effective tool to study crashes and evaluate injury mechanisms, and using stochastic input data, whole populations of crashes can be studied. The aim of this study was to develop a generic buck <span class="hlt">model</span> and to <span class="hlt">validate</span> this <span class="hlt">model</span> on a population of real-life frontal crashes in terms of the risk of rib fracture. The study was conducted in four phases. In the first phase, real-life <span class="hlt">validation</span> data were derived by analyzing NASS/CDS data to find the relationship between injury risk and crash parameters. In addition, available statistical distributions for the parameters were collected. In the second phase, a generic parameterized finite element (<span class="hlt">FE</span>) <span class="hlt">model</span> of a vehicle interior was developed based on laser scans from the A2MAC1 database. In the third phase, <span class="hlt">model</span> parameters that could not be found in the literature were estimated using reverse engineering based on NCAP tests. Finally, in the fourth phase, the stochastic <span class="hlt">FE</span> <span class="hlt">model</span> was used to simulate a population of real-life crashes, and the result was compared to the <span class="hlt">validation</span> data from phase one. The stochastic <span class="hlt">FE</span> simulation <span class="hlt">model</span> overestimates the risk of rib fracture, more for young occupants and less for senior occupants. However, if the effect of underestimation of rib fractures in the NASS/CDS material is accounted for using statistical simulations, the risk of rib fracture based on the stochastic <span class="hlt">FE</span> <span class="hlt">model</span> matches the risk based on the NASS/CDS data for senior occupants. The current version of the stochastic <span class="hlt">model</span> can be used to evaluate new safety measures using a population of frontal crashes for senior occupants. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1352774-thermodynamic-kinetic-modeling-grain-boundary-equilibrium-segregation-fe','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1352774-thermodynamic-kinetic-modeling-grain-boundary-equilibrium-segregation-fe"><span>Thermodynamic and kinetic <span class="hlt">modeling</span> of grain boundary equilibrium segregation of P in α-<span class="hlt">Fe</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Yang, Y.; Chen, S. -L.</p> <p>2017-04-18</p> <p>Phosphorus is a primary contributor to interface fracture and embrittlement in steels because of its strong segregation tendency at grain boundaries (GBs). The lack of consistency in literature data imposes great difficulties in performing segregation <span class="hlt">modeling</span> that is compatible with both the Langmuir-Mclean segregation theory and the thermodynamic description of the Bcc(<span class="hlt">Fe</span>,P) phase. Our work carefully evaluated experimental data for phosphorus segregation at GBs in -<span class="hlt">Fe</span> and provided a new formula for converting the auger electron spectroscopy (AES) peak height ratio to GBs. Furthermore, based on newly assessed literature data, this work proposes that the major driving force for phosphorusmore » segregation is the formation of <span class="hlt">Fe</span> 3P-type clusters at GBs, which is supported not only by the almost equivalent Gibbs energy of _<span class="hlt">Fe</span> using the Bcc(<span class="hlt">Fe</span>,P) substitutional <span class="hlt">model</span> and the Bcc(<span class="hlt">Fe,Fe</span> 3P, P) associate <span class="hlt">model</span>, but also by the good agreement between thermodynamic/kinetic <span class="hlt">modeling</span> results and experimental data.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12547369','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12547369"><span>Concept and development of an orthotropic <span class="hlt">FE</span> <span class="hlt">model</span> of the proximal femur.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wirtz, Dieter Christian; Pandorf, Thomas; Portheine, Frank; Radermacher, Klaus; Schiffers, Norbert; Prescher, Andreas; Weichert, Dieter; Niethard, Fritz Uwe</p> <p>2003-02-01</p> <p>In contrast to many isotropic finite-element (<span class="hlt">FE</span>) <span class="hlt">models</span> of the femur in literature, it was the object of our study to develop an orthotropic <span class="hlt">FE</span> "<span class="hlt">model</span> femur" to realistically simulate three-dimensional bone remodelling. The three-dimensional geometry of the proximal femur was reconstructed by CT scans of a pair of cadaveric femurs at equal distances of 2mm. These three-dimensional CT <span class="hlt">models</span> were implemented into an <span class="hlt">FE</span> simulation tool. Well-known "density-determined" bony material properties (Young's modulus; Poisson's ratio; ultimate strength in pressure, tension and torsion; shear modulus) were assigned to each <span class="hlt">FE</span> of the same "CT-density-characterized" volumetric group. In order to fix the principal directions of stiffness in <span class="hlt">FE</span> areas with the same "density characterization", the cadaveric femurs were cut in 2mm slices in frontal (left femur) and sagittal plane (right femur). Each femoral slice was scanned into a computer-based image processing system. On these images, the principal directions of stiffness of cancellous and cortical bone were determined manually using the orientation of the trabecular structures and the Haversian system. Finally, these geometric data were matched with the "CT-density characterized" three-dimensional femur <span class="hlt">model</span>. In addition, the time and density-dependent adaptive behaviour of bone remodelling was taken into account by implementation of Carter's criterion. In the constructed "<span class="hlt">model</span> femur", each <span class="hlt">FE</span> is characterized by the principal directions of the stiffness and the "CT-density-determined" material properties of cortical and cancellous bone. Thus, on the basis of anatomic data a three-dimensional <span class="hlt">FE</span> simulation reference <span class="hlt">model</span> of the proximal femur was realized considering orthotropic conditions of bone behaviour. With the orthotropic "<span class="hlt">model</span> femur", the fundamental basis has been formed to realize realistic simulations of the dynamical processes of bone remodelling under different loading conditions or operative procedures</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24975696','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24975696"><span>Development of structural and material clavicle response corridors under axial compression and three point bending loading for clavicle finite element <span class="hlt">model</span> <span class="hlt">validation</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Qi; Kindig, Matthew; Li, Zuoping; Crandall, Jeff R; Kerrigan, Jason R</p> <p>2014-08-22</p> <p>Clavicle injuries were frequently observed in automotive side and frontal crashes. Finite element (<span class="hlt">FE</span>) <span class="hlt">models</span> have been developed to understand the injury mechanism, although no clavicle loading response corridors yet exist in the literature to ensure the <span class="hlt">model</span> response biofidelity. Moreover, the typically developed structural level (e.g., force-deflection) response corridors were shown to be insufficient for verifying the injury prediction capacity of <span class="hlt">FE</span> <span class="hlt">model</span>, which usually is based on strain related injury criteria. Therefore, the purpose of this study is to develop both the structural (force vs deflection) and material level (strain vs force) clavicle response corridors for <span class="hlt">validating</span> <span class="hlt">FE</span> <span class="hlt">models</span> for injury risk <span class="hlt">modeling</span>. 20 Clavicles were loaded to failure under loading conditions representative of side and frontal crashes respectively, half of which in axial compression, and the other half in three point bending. Both structural and material response corridors were developed for each loading condition. <span class="hlt">FE</span> <span class="hlt">model</span> that can accurately predict structural response and strain level provides a more useful tool in injury risk <span class="hlt">modeling</span> and prediction. The corridor development method in this study could also be extended to develop corridors for other components of the human body. Copyright © 2014 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1351763-mechanical-properties-neutron-irradiated-model-commercial-fecral-alloys','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1351763-mechanical-properties-neutron-irradiated-model-commercial-fecral-alloys"><span>Mechanical properties of neutron-irradiated <span class="hlt">model</span> and commercial <span class="hlt">Fe</span>CrAl alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Field, Kevin G.; Briggs, Samuel A.; Sridharan, Kumar; ...</p> <p>2017-03-28</p> <p>The development and understanding of the mechanical properties of neutron-irradiated <span class="hlt">Fe</span>CrAl alloys is increasingly a critical need as these alloys continue to become more mature for nuclear reactor applications. This study focuses on the mechanical properties of <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys and of a commercial <span class="hlt">Fe</span>CrAl alloy neutron-irradiated to up to 13.8 displacements per atom (dpa) at irradiation temperatures between 320 and 382 °C. Tensile tests were completed at room temperature and at 320 °C, and a subset of fractured tensile specimens was examined by scanning electron microscopy. Results showed typical radiation hardening and embrittlement indicative of high chromium ferritic alloysmore » with strong chromium composition dependencies at lower doses. At and above 7.0 dpa, the mechanical properties saturated for both the commercial and <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys, although brittle cleavage fracture was observed at the highest dose in the <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloy with the highest chromium content (18 wt %). Finally, the results suggest the composition and microstructure of <span class="hlt">Fe</span>CrAl alloys plays a critical role in the mechanical response of <span class="hlt">Fe</span>CrAl alloys irradiated near temperatures relevant to light water reactors.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.4186L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.4186L"><span>Coupled cycling of <span class="hlt">Fe</span> and organic carbon in submarine hydrothermal systems: <span class="hlt">Modelling</span> approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Legendre, Louis; German, Christopher R.; Sander, Sylvia G.; Niquil, Nathalie</p> <p>2014-05-01</p> <p>It has been recently proposed that hydrothermal plumes may be a significant source of dissolved <span class="hlt">Fe</span> to the oceans. In order to assess this proposal, we investigated the fate of dissolved <span class="hlt">Fe</span> released from hydrothermal systems to the overlying ocean using an approach that combined <span class="hlt">modelling</span> and field values. We based our work on a consensus conceptual <span class="hlt">model</span> developed by members of SCOR-InterRidge Working Group 135. The <span class="hlt">model</span> was both complex enough to capture the main processes of dissolved <span class="hlt">Fe</span> released from hydrothermal systems and chemical transformation in the hydrothermal plume, and simple enough to be parameterized with existing field data. It included the following flows: <span class="hlt">Fe</span>, water and heat in the high temperature vent fluids, in the fluids diffusing around the vent, and in the entrained seawater in the buoyant plume; <span class="hlt">Fe</span> precipitation in polymetallic sulphides near the vent; transport of <span class="hlt">Fe</span> in the non-buoyant plume, and both its precipitation in particles onto the sea bottom away from the vent and dissolution into deep-sea waters. In other words, there were three <span class="hlt">Fe</span> input flows into the buoyant hydrothermal plume (vent-fluids; entrained diffuse flow; entrained seawater) and three <span class="hlt">Fe</span> output flows (sedimentation from the buoyant plume as polymetallic sulfides; sedimentation from the non-buoyant plume in particulate form; export to the deep ocean in dissolved or nanoparticulate form). The output flows balanced the input flows. We transformed the conceptual <span class="hlt">model</span> into equations, and parameterized these with field data. To do so, we assumed that all hydrothermal systems, globally, can be represented by the circumstances that prevail at the EPR 9°50'N hydrothermal field, although we knew this assumption not to be accurate. We nevertheless achieved, by following this approach, two important goals, i.e. we could assemble into a coherent framework, for the first time, several discrete data sets acquired independently over decades of field work, and we could obtain <span class="hlt">model</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21280884','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21280884"><span>Biomechanical <span class="hlt">validation</span> of finite element <span class="hlt">models</span> for two silicone metacarpophalangeal joint implants.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hussein, A I; Stranart, J C; Meguid, S A; Bogoch, E R</p> <p>2011-02-01</p> <p>Silicone implants are used for prosthetic arthroplasty of metacarpophalangeal (MCP) joints severely damaged by rheumatoid arthritis. Different silicone elastomer MCP implant designs have been developed, including the Swanson and the NeuFlex implants. The goal of this study was to compare the in vitro mechanical behavior of Swanson and NeuFlex MCP joint implants. Three-dimensional (3D) finite element (<span class="hlt">FE</span>) <span class="hlt">models</span> of the silicone implants were <span class="hlt">modeled</span> using the commercial software ANSYS and subjected to angular displacement from 0 deg to 90 deg. <span class="hlt">FE</span> <span class="hlt">models</span> were <span class="hlt">validated</span> using mechanical tests of implants incrementally bent from 0 deg to 90 deg in a joint simulator. Swanson size 2 and 4 implants were compared with NeuFlex size 10 and 30 implants, respectively. Good agreement was observed throughout the range of motion for the flexion bending moment derived from 3D <span class="hlt">FE</span> <span class="hlt">models</span> and mechanical tests. From 30 deg to 90 deg, the Swanson 2 demonstrated a greater resistance to deformation than the NeuFlex 10 and required a greater bending moment for joint flexion. For larger implant sizes, the NeuFlex 30 had a steeper moment-displacement curve, but required a lower moment than the Swanson 4, due to implant preflexion. On average, the stress generated at the implant hinge from 30 deg to 90 deg was lower in the NeuFlex than in the Swanson. On average, starting from the neutral position of 30 deg for the preflexed NeuFlex implant, higher moments were required to extend the NeuFlex implants to 0 deg compared with the Swanson implants, which returned spontaneously to resting position. Implant toggling within the medullary canals was less in the NeuFlex than in the Swanson. The differential performance of these implants may be useful in implant selection based on the preoperative condition(s) of the joint and specific patient functional needs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1376391-dislocation-loop-evolution-during-situ-ion-irradiation-model-fecral-alloys','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1376391-dislocation-loop-evolution-during-situ-ion-irradiation-model-fecral-alloys"><span>Dislocation loop evolution during in-situ ion irradiation of <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Haley, Jack C.; Briggs, Samuel A.; Edmondson, Philip D.</p> <p></p> <p><span class="hlt">Model</span> <span class="hlt">Fe</span>CrAl alloys of <span class="hlt">Fe</span>-10%Cr-5%Al, <span class="hlt">Fe</span>-12%Cr-4.5%Al, <span class="hlt">Fe</span>-15%Cr-4%Al, and <span class="hlt">Fe</span>-18%Cr-3%Al (in wt %) were irradiated with 1 MeV Kr++ ions in-situ with transmission electron microscopy to a dose of 2.5 displacements per atom (dpa) at 320 °C. In all cases, the microstructural damage consisted of dislocation loops with ½< 111 > and <100 > Burgers vectors. The proportion of ½< 111 > dislocation loops varied from ~50% in the <span class="hlt">Fe</span>-10%Cr-5%Al <span class="hlt">model</span> alloy and the <span class="hlt">Fe</span>-18Cr%-3%Al <span class="hlt">model</span> alloy to a peak of ~80% in the <span class="hlt">model</span> <span class="hlt">Fe</span>-15%Cr-4.5%Al alloy. The dislocation loop volume density increased with dose for all alloys and showed signsmore » of approaching an upper limit. The total loop populations at 2.5 dpa had a slight (and possibly insignificant) decline as the chromium content was increased from 10 to 15 wt %, but the <span class="hlt">Fe</span>-18%Cr-3%Al alloy had a dislocation loop population ~50% smaller than the other <span class="hlt">model</span> alloys. As a result, the largest dislocation loops in each alloy had image sizes of close to 20 nm in the micrographs, and the median diameters for all alloys ranged from 6 to 8 nm. Nature analysis by the inside-outside method indicated most dislocation loops were interstitial type.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1376391-dislocation-loop-evolution-during-situ-ion-irradiation-model-fecral-alloys','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1376391-dislocation-loop-evolution-during-situ-ion-irradiation-model-fecral-alloys"><span>Dislocation loop evolution during in-situ ion irradiation of <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Haley, Jack C.; Briggs, Samuel A.; Edmondson, Philip D.; ...</p> <p>2017-07-06</p> <p><span class="hlt">Model</span> <span class="hlt">Fe</span>CrAl alloys of <span class="hlt">Fe</span>-10%Cr-5%Al, <span class="hlt">Fe</span>-12%Cr-4.5%Al, <span class="hlt">Fe</span>-15%Cr-4%Al, and <span class="hlt">Fe</span>-18%Cr-3%Al (in wt %) were irradiated with 1 MeV Kr++ ions in-situ with transmission electron microscopy to a dose of 2.5 displacements per atom (dpa) at 320 °C. In all cases, the microstructural damage consisted of dislocation loops with ½< 111 > and <100 > Burgers vectors. The proportion of ½< 111 > dislocation loops varied from ~50% in the <span class="hlt">Fe</span>-10%Cr-5%Al <span class="hlt">model</span> alloy and the <span class="hlt">Fe</span>-18Cr%-3%Al <span class="hlt">model</span> alloy to a peak of ~80% in the <span class="hlt">model</span> <span class="hlt">Fe</span>-15%Cr-4.5%Al alloy. The dislocation loop volume density increased with dose for all alloys and showed signsmore » of approaching an upper limit. The total loop populations at 2.5 dpa had a slight (and possibly insignificant) decline as the chromium content was increased from 10 to 15 wt %, but the <span class="hlt">Fe</span>-18%Cr-3%Al alloy had a dislocation loop population ~50% smaller than the other <span class="hlt">model</span> alloys. As a result, the largest dislocation loops in each alloy had image sizes of close to 20 nm in the micrographs, and the median diameters for all alloys ranged from 6 to 8 nm. Nature analysis by the inside-outside method indicated most dislocation loops were interstitial type.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4813892','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4813892"><span>SHM-Based Probabilistic Fatigue Life Prediction for Bridges Based on <span class="hlt">FE</span> <span class="hlt">Model</span> Updating</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lee, Young-Joo; Cho, Soojin</p> <p>2016-01-01</p> <p>Fatigue life prediction for a bridge should be based on the current condition of the bridge, and various sources of uncertainty, such as material properties, anticipated vehicle loads and environmental conditions, make the prediction very challenging. This paper presents a new approach for probabilistic fatigue life prediction for bridges using finite element (<span class="hlt">FE</span>) <span class="hlt">model</span> updating based on structural health monitoring (SHM) data. Recently, various types of SHM systems have been used to monitor and evaluate the long-term structural performance of bridges. For example, SHM data can be used to estimate the degradation of an in-service bridge, which makes it possible to update the initial <span class="hlt">FE</span> <span class="hlt">model</span>. The proposed method consists of three steps: (1) identifying the modal properties of a bridge, such as mode shapes and natural frequencies, based on the ambient vibration under passing vehicles; (2) updating the structural parameters of an initial <span class="hlt">FE</span> <span class="hlt">model</span> using the identified modal properties; and (3) predicting the probabilistic fatigue life using the updated <span class="hlt">FE</span> <span class="hlt">model</span>. The proposed method is demonstrated by application to a numerical <span class="hlt">model</span> of a bridge, and the impact of <span class="hlt">FE</span> <span class="hlt">model</span> updating on the bridge fatigue life is discussed. PMID:26950125</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1850i0002A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1850i0002A"><span>Experimental and thermodynamic study of Co-<span class="hlt">Fe</span> and Mn-<span class="hlt">Fe</span> based mixed metal oxides for thermochemical energy storage application</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>André, Laurie; Abanades, Stéphane; Cassayre, Laurent</p> <p>2017-06-01</p> <p>Metal oxides are potential materials for thermochemical heat storage, and among them, cobalt oxide and manganese oxide are attracting attention. Furthermore, studies on mixed oxides are ongoing, as the synthesis of mixed oxides could be a way to answer the drawbacks of pure metal oxides, such as slow reaction kinetics, loss-in-capacity over cycles or sintering, selected for thermochemical heat storage application. The addition of iron oxide is under investigation and the obtained results are presented. This work proposes a comparison of thermodynamic <span class="hlt">modelling</span> with experimental data in order to identify the impact of iron oxide addition to cobalt oxide and manganese oxide. <span class="hlt">Fe</span> addition decreased the redox activity and energy storage capacity of Co3O4, whereas the cycling stability of Mn2O3 was significantly improved with added <span class="hlt">Fe</span> amounts above 20 mol% while the energy storage capacity was unchanged. The thermodynamic <span class="hlt">modelling</span> method to predict the behavior of the Mn-<span class="hlt">Fe</span>-O and Co-<span class="hlt">Fe</span>-O systems was <span class="hlt">validated</span>, and the possibility to identify other mixed oxides becomes conceivable, by enabling the selection of transition metals additives for metal oxides destined for thermochemical energy storage applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120001214','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120001214"><span>Base Flow <span class="hlt">Model</span> <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sinha, Neeraj; Brinckman, Kevin; Jansen, Bernard; Seiner, John</p> <p>2011-01-01</p> <p>A method was developed of obtaining propulsive base flow data in both hot and cold jet environments, at Mach numbers and altitude of relevance to NASA launcher designs. The base flow data was used to perform computational fluid dynamics (CFD) turbulence <span class="hlt">model</span> assessments of base flow predictive capabilities in order to provide increased confidence in base thermal and pressure load predictions obtained from computational <span class="hlt">modeling</span> efforts. Predictive CFD analyses were used in the design of the experiments, available propulsive <span class="hlt">models</span> were used to reduce program costs and increase success, and a wind tunnel facility was used. The data obtained allowed assessment of CFD/turbulence <span class="hlt">models</span> in a complex flow environment, working within a building-block procedure to <span class="hlt">validation</span>, where cold, non-reacting test data was first used for <span class="hlt">validation</span>, followed by more complex reacting base flow <span class="hlt">validation</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MMTA...47.4970T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MMTA...47.4970T"><span>Precipitation <span class="hlt">Modeling</span> in Nitriding in <span class="hlt">Fe</span>-M Binary System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tomio, Yusaku; Miyamoto, Goro; Furuhara, Tadashi</p> <p>2016-10-01</p> <p>Precipitation of fine alloy nitrides near the specimen surface results in significant surface hardening in nitriding of alloyed steels. In this study, a simulation <span class="hlt">model</span> of alloy nitride precipitation during nitriding is developed for <span class="hlt">Fe</span>-M binary system based upon the Kampmann-Wagner numerical <span class="hlt">model</span> in order to predict variations in the distribution of precipitates with depth. The <span class="hlt">model</span> can predict the number density, average radius, and volume fraction of alloy nitrides as a function of depth from the surface and nitriding time. By a comparison with the experimental observation in a nitrided <span class="hlt">Fe</span>-Cr alloy, it was found that the <span class="hlt">model</span> can predict successfully the observed particle distribution from the surface into depth when appropriate solubility of CrN, interfacial energy between CrN and α, and nitrogen flux at the surface are selected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CoMP..171...74K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CoMP..171...74K"><span>Melting relations in the system <span class="hlt">Fe</span>CO3-MgCO3 and thermodynamic <span class="hlt">modelling</span> of <span class="hlt">Fe</span>-Mg carbonate melts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kang, Nathan; Schmidt, Max W.; Poli, Stefano; Connolly, James A. D.; Franzolin, Ettore</p> <p>2016-09-01</p> <p>To constrain the thermodynamics and melting relations of the siderite-magnesite (<span class="hlt">Fe</span>CO3-MgCO3) system, 27 piston cylinder experiments were conducted at 3.5 GPa and 1170-1575 °C. <span class="hlt">Fe</span>-rich compositions were also investigated with 13 multi-anvil experiments at 10, 13.6 and 20 GPa, 1500-1890 °C. At 3.5 GPa, the solid solution siderite-magnesite coexists with melt over a compositional range of X Mg (=Mg/(Mg + Fetot)) = 0.38-1.0, while at ≥10 GPa solid solution appears to be complete. At 3.5 GPa, the system is pseudo-binary because of the limited stability of siderite or liquid <span class="hlt">Fe</span>CO3, <span class="hlt">Fe</span>-rich carbonates decomposing at subsolidus conditions to magnetite-magnesioferrite solid solution, graphite and CO2. Similar reactions also occur with liquid <span class="hlt">Fe</span>CO3 resulting in melt species with ferric iron components, but the decomposition of the liquid decreases in importance with pressure. At 3.5 GPa, the metastable melting temperature of pure siderite is located at 1264 °C, whereas pure magnesite melts at 1629 °C. The melting loop is non-ideal on the <span class="hlt">Fe</span> side where the dissociation reaction resulting in <span class="hlt">Fe</span>3+ in the melt depresses melting temperatures and causes a minimum. Over the pressure range of 3.5-20 GPa, this minimum is 20-35 °C lower than the (metastable) siderite melting temperature. By merging all present and previous experimental data, standard state (298.15 K, 1 bar) thermodynamic properties of the magnesite melt (MgCO3L) end member are calculated and the properties of (<span class="hlt">Fe</span>,Mg)CO3 melt fit by a regular solution <span class="hlt">model</span> with an interaction parameter of -7600 J/mol. The solution <span class="hlt">model</span> reproduces the asymmetric melting loop and predicts the thermal minimum at 1240 °C near the siderite side at X Mg = 0.2 (3.5 GPa). The solution <span class="hlt">model</span> is applicable to pressures reaching to the bottom of the upper mantle and allows calculation of phase relations in the <span class="hlt">Fe</span>O-MgO-O2-C system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28553201','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28553201"><span><span class="hlt">Fe</span>65-PTB2 Dimerization Mimics <span class="hlt">Fe</span>65-APP Interaction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Feilen, Lukas P; Haubrich, Kevin; Strecker, Paul; Probst, Sabine; Eggert, Simone; Stier, Gunter; Sinning, Irmgard; Konietzko, Uwe; Kins, Stefan; Simon, Bernd; Wild, Klemens</p> <p>2017-01-01</p> <p>Physiological function and pathology of the Alzheimer's disease causing amyloid precursor protein (APP) are correlated with its cytosolic adaptor <span class="hlt">Fe</span>65 encompassing a WW and two phosphotyrosine-binding domains (PTBs). The C-terminal <span class="hlt">Fe</span>65-PTB2 binds a large portion of the APP intracellular domain (AICD) including the GYENPTY internalization sequence fingerprint. AICD binding to <span class="hlt">Fe</span>65-PTB2 opens an intra-molecular interaction causing a structural change and altering <span class="hlt">Fe</span>65 activity. Here we show that in the absence of the AICD, <span class="hlt">Fe</span>65-PTB2 forms a homodimer in solution and determine its crystal structure at 2.6 Å resolution. Dimerization involves the unwinding of a C-terminal α-helix that mimics binding of the AICD internalization sequence, thus shielding the hydrophobic binding pocket. Specific dimer formation is <span class="hlt">validated</span> by nuclear magnetic resonance (NMR) techniques and cell-based analyses reveal that <span class="hlt">Fe</span>65-PTB2 together with the WW domain are necessary and sufficient for dimerization. Together, our data demonstrate that <span class="hlt">Fe</span>65 dimerizes via its APP interaction site, suggesting that besides intra- also intermolecular interactions between <span class="hlt">Fe</span>65 molecules contribute to homeostatic regulation of APP mediated signaling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5425604','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5425604"><span><span class="hlt">Fe</span>65-PTB2 Dimerization Mimics <span class="hlt">Fe</span>65-APP Interaction</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Feilen, Lukas P.; Haubrich, Kevin; Strecker, Paul; Probst, Sabine; Eggert, Simone; Stier, Gunter; Sinning, Irmgard; Konietzko, Uwe; Kins, Stefan; Simon, Bernd; Wild, Klemens</p> <p>2017-01-01</p> <p>Physiological function and pathology of the Alzheimer’s disease causing amyloid precursor protein (APP) are correlated with its cytosolic adaptor <span class="hlt">Fe</span>65 encompassing a WW and two phosphotyrosine-binding domains (PTBs). The C-terminal <span class="hlt">Fe</span>65-PTB2 binds a large portion of the APP intracellular domain (AICD) including the GYENPTY internalization sequence fingerprint. AICD binding to <span class="hlt">Fe</span>65-PTB2 opens an intra-molecular interaction causing a structural change and altering <span class="hlt">Fe</span>65 activity. Here we show that in the absence of the AICD, <span class="hlt">Fe</span>65-PTB2 forms a homodimer in solution and determine its crystal structure at 2.6 Å resolution. Dimerization involves the unwinding of a C-terminal α-helix that mimics binding of the AICD internalization sequence, thus shielding the hydrophobic binding pocket. Specific dimer formation is <span class="hlt">validated</span> by nuclear magnetic resonance (NMR) techniques and cell-based analyses reveal that <span class="hlt">Fe</span>65-PTB2 together with the WW domain are necessary and sufficient for dimerization. Together, our data demonstrate that <span class="hlt">Fe</span>65 dimerizes via its APP interaction site, suggesting that besides intra- also intermolecular interactions between <span class="hlt">Fe</span>65 molecules contribute to homeostatic regulation of APP mediated signaling. PMID:28553201</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.454.2549B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.454.2549B"><span>Spectral <span class="hlt">models</span> for early time SN 2011<span class="hlt">fe</span> observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baron, E.; Hoeflich, P.; Friesen, Brian; Sullivan, M.; Hsiao, E.; Ellis, R. S.; Gal-Yam, A.; Howell, D. A.; Nugent, P. E.; Dominguez, I.; Krisciunas, K.; Phillips, M. M.; Suntzeff, N.; Wang, L.; Thomas, R. C.</p> <p>2015-12-01</p> <p>We use observed UV through near-IR spectra to examine whether SN 2011<span class="hlt">fe</span> can be understood in the framework of Branch-normal Type Ia supernovae (SNe Ia) and to examine its individual peculiarities. As a benchmark, we use a delayed-detonation <span class="hlt">model</span> with a progenitor metallicity of Z⊙/20. We study the sensitivity of features to variations in progenitor metallicity, the outer density profile, and the distribution of radioactive nickel. The effect of metallicity variations in the progenitor have a relatively small effect on the synthetic spectra. We also find that the abundance stratification of SN 2011<span class="hlt">fe</span> resembles closely that of a delayed-detonation <span class="hlt">model</span> with a transition density that has been fit to other Branch-normal SNe Ia. At early times, the <span class="hlt">model</span> photosphere is formed in material with velocities that are too high, indicating that the photosphere recedes too slowly or that SN 2011<span class="hlt">fe</span> has a lower specific energy in the outer ≈0.1 M⊙ than does the <span class="hlt">model</span>. We discuss several explanations for the discrepancies. Finally, we examine variations in both the spectral energy distribution and in the colours due to variations in the progenitor metallicity, which suggests that colours are only weak indicators for the progenitor metallicity, in the particular explosion <span class="hlt">model</span> that we have studied. We do find that the flux in the U band is significantly higher at maximum light in the solar metallicity <span class="hlt">model</span> than in the lower metallicity <span class="hlt">model</span> and the lower metallicity <span class="hlt">model</span> much better matches the observed spectrum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26027974','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26027974"><span>Development and <span class="hlt">Validation</span> of the Total HUman <span class="hlt">Model</span> for Safety (THUMS) Toward Further Understanding of Occupant Injury Mechanisms in Precrash and During Crash.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Iwamoto, Masami; Nakahira, Yuko; Kimpara, Hideyuki</p> <p>2015-01-01</p> <p>Active safety devices such as automatic emergency brake (AEB) and precrash seat belt have the potential to accomplish further reduction in the number of the fatalities due to automotive accidents. However, their effectiveness should be investigated by more accurate estimations of their interaction with human bodies. Computational human body <span class="hlt">models</span> are suitable for investigation, especially considering muscular tone effects on occupant motions and injury outcomes. However, the conventional <span class="hlt">modeling</span> approaches such as multibody <span class="hlt">models</span> and detailed finite element (<span class="hlt">FE</span>) <span class="hlt">models</span> have advantages and disadvantages in computational costs and injury predictions considering muscular tone effects. The objective of this study is to develop and <span class="hlt">validate</span> a human body <span class="hlt">FE</span> <span class="hlt">model</span> with whole body muscles, which can be used for the detailed investigation of interaction between human bodies and vehicular structures including some safety devices precrash and during a crash with relatively low computational costs. In this study, we developed a human body <span class="hlt">FE</span> <span class="hlt">model</span> called THUMS (Total HUman <span class="hlt">Model</span> for Safety) with a body size of 50th percentile adult male (AM50) and a sitting posture. The <span class="hlt">model</span> has anatomical structures of bones, ligaments, muscles, brain, and internal organs. The total number of elements is 281,260, which would realize relatively low computational costs. Deformable material <span class="hlt">models</span> were assigned to all body parts. The muscle-tendon complexes were <span class="hlt">modeled</span> by truss elements with Hill-type muscle material and seat belt elements with tension-only material. The THUMS was <span class="hlt">validated</span> against 35 series of cadaver or volunteer test data on frontal, lateral, and rear impacts. <span class="hlt">Model</span> <span class="hlt">validations</span> for 15 series of cadaver test data associated with frontal impacts are presented in this article. The THUMS with a vehicle sled <span class="hlt">model</span> was applied to investigate effects of muscle activations on occupant kinematics and injury outcomes in specific frontal impact situations with AEB. In the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1389187','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1389187"><span>Literature review report on atomistic <span class="hlt">modeling</span> tools for <span class="hlt">Fe</span>CrAl alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Zhang, Yongfeng; Schwen, Daniel; Martinez, Enrique</p> <p>2015-12-01</p> <p>This reports summarizes the literature review results on atomistic tools, particularly interatomic potentials used in molecular dynamics simulations, for <span class="hlt">Fe</span>CrAl ternary alloys. <span class="hlt">Fe</span>CrAl has recently been identified as a possible cladding concept for accident tolerant fuels for its superior corrosion resistance. Along with several other concepts, an initial evaluation and recommendation are desired for <span class="hlt">Fe</span>CrAl before it’s used in realistic fuels. For this purpose, sufficient understanding on the in-reactor behavior of <span class="hlt">Fe</span>CrAl needs to be grained in a relatively short timeframe, and multiscale <span class="hlt">modeling</span> and simulations have been selected as an efficient measure to supplement experiments and in-reactor testing formore » better understanding on <span class="hlt">Fe</span>CrAl. For the limited knowledge on <span class="hlt">Fe</span>CrAl alloys, the multiscale <span class="hlt">modeling</span> approach relies on atomistic simulations to obtain the missing material parameters and properties. As a first step, atomistic tools have to be identified and this is the purpose of the present report. It was noticed during the literature survey that no interatomic potentials currently available for <span class="hlt">Fe</span>CrAl. Here, we summarize the interatomic potentials available for <span class="hlt">Fe</span>Cr alloys for possible molecular dynamics studies using <span class="hlt">Fe</span>Cr as surrogate materials. Other atomistic methods such as lattice kinetic Monte Carlo are also included in this report. A couple of research topics at the atomic scale are suggested based on the literature survey.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.H11E0895K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.H11E0895K"><span><span class="hlt">Validation</span> of Groundwater <span class="hlt">Models</span>: Meaningful or Meaningless?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Konikow, L. F.</p> <p>2003-12-01</p> <p>Although numerical simulation <span class="hlt">models</span> are valuable tools for analyzing groundwater systems, their predictive accuracy is limited. People who apply groundwater flow or solute-transport <span class="hlt">models</span>, as well as those who make decisions based on <span class="hlt">model</span> results, naturally want assurance that a <span class="hlt">model</span> is "<span class="hlt">valid</span>." To many people, <span class="hlt">model</span> <span class="hlt">validation</span> implies some authentication of the truth or accuracy of the <span class="hlt">model</span>. History matching is often presented as the basis for <span class="hlt">model</span> <span class="hlt">validation</span>. Although such <span class="hlt">model</span> calibration is a necessary <span class="hlt">modeling</span> step, it is simply insufficient for <span class="hlt">model</span> <span class="hlt">validation</span>. Because of parameter uncertainty and solution non-uniqueness, declarations of <span class="hlt">validation</span> (or verification) of a <span class="hlt">model</span> are not meaningful. Post-audits represent a useful means to assess the predictive accuracy of a site-specific <span class="hlt">model</span>, but they require the existence of long-term monitoring data. <span class="hlt">Model</span> testing may yield invalidation, but that is an opportunity to learn and to improve the conceptual and numerical <span class="hlt">models</span>. Examples of post-audits and of the application of a solute-transport <span class="hlt">model</span> to a radioactive waste disposal site illustrate deficiencies in <span class="hlt">model</span> calibration, prediction, and <span class="hlt">validation</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1407294-spectral-models-early-time-sn-observations','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1407294-spectral-models-early-time-sn-observations"><span>Spectral <span class="hlt">models</span> for early time SN 2011<span class="hlt">fe</span> observations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Baron, E.; Hoeflich, P.; Friesen, Brian; ...</p> <p>2015-10-13</p> <p>We use observed UV through near-IR spectra to examine whether SN 2011<span class="hlt">fe</span> can be understood in the framework of Branch-normal Type Ia supernovae (SNe Ia) and to examine its individual peculiarities. As a benchmark, we use a delayed-detonationmodel with a progenitormetallicity of Z ⊙/20. We study the sensitivity of features to variations in progenitor metallicity, the outer density profile, and the distribution of radioactive nickel. The effect of metallicity variations in the progenitor have a relatively small effect on the synthetic spectra. We also find that the abundance stratification of SN 2011<span class="hlt">fe</span> resembles closely that of a delayed-detonation <span class="hlt">model</span> withmore » a transition density that has been fit to other Branch-normal SNe Ia. At early times, the <span class="hlt">model</span> photosphere is formed in material with velocities that are too high, indicating that the photosphere recedes too slowly or that SN 2011<span class="hlt">fe</span> has a lower specific energy in the outer ≈0.1 M ⊙ than does the <span class="hlt">model</span>. We discuss several explanations for the discrepancies. Lastly, we examine variations in both the spectral energy distribution and in the colours due to variations in the progenitor metallicity, which suggests that colours are only weak indicators for the progenitor metallicity, in the particular explosion <span class="hlt">model</span> that we have studied. Here we do find that the flux in the U band is significantly higher at maximum light in the solar metallicity <span class="hlt">model</span> than in the lower metallicity <span class="hlt">model</span> and the lower metallicity <span class="hlt">model</span> much better matches the observed spectrum.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70018505','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70018505"><span>Testing and <span class="hlt">validating</span> environmental <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kirchner, J.W.; Hooper, R.P.; Kendall, C.; Neal, C.; Leavesley, G.</p> <p>1996-01-01</p> <p>Generally accepted standards for testing and <span class="hlt">validating</span> ecosystem <span class="hlt">models</span> would benefit both <span class="hlt">modellers</span> and <span class="hlt">model</span> users. Universally applicable test procedures are difficult to prescribe, given the diversity of <span class="hlt">modelling</span> approaches and the many uses for <span class="hlt">models</span>. However, the generally accepted scientific principles of documentation and disclosure provide a useful framework for devising general standards for <span class="hlt">model</span> evaluation. Adequately documenting <span class="hlt">model</span> tests requires explicit performance criteria, and explicit benchmarks against which <span class="hlt">model</span> performance is compared. A <span class="hlt">model</span>'s <span class="hlt">validity</span>, reliability, and accuracy can be most meaningfully judged by explicit comparison against the available alternatives. In contrast, current practice is often characterized by vague, subjective claims that <span class="hlt">model</span> predictions show 'acceptable' agreement with data; such claims provide little basis for choosing among alternative <span class="hlt">models</span>. Strict <span class="hlt">model</span> tests (those that invalid <span class="hlt">models</span> are unlikely to pass) are the only ones capable of convincing rational skeptics that a <span class="hlt">model</span> is probably <span class="hlt">valid</span>. However, 'false positive' rates as low as 10% can substantially erode the power of <span class="hlt">validation</span> tests, making them insufficiently strict to convince rational skeptics. <span class="hlt">Validation</span> tests are often undermined by excessive parameter calibration and overuse of ad hoc <span class="hlt">model</span> features. Tests are often also divorced from the conditions under which a <span class="hlt">model</span> will be used, particularly when it is designed to forecast beyond the range of historical experience. In such situations, data from laboratory and field manipulation experiments can provide particularly effective tests, because one can create experimental conditions quite different from historical data, and because experimental data can provide a more precisely defined 'target' for the <span class="hlt">model</span> to hit. We present a simple demonstration showing that the two most common methods for comparing <span class="hlt">model</span> predictions to environmental time series (plotting <span class="hlt">model</span> time series</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPS...375..106L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPS...375..106L"><span><span class="hlt">Modeling</span> the degradation mechanisms of C6/Li<span class="hlt">Fe</span>PO4 batteries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Dongjiang; Danilov, Dmitri L.; Zwikirsch, Barbara; Fichtner, Maximilian; Yang, Yong; Eichel, Rüdiger-A.; Notten, Peter H. L.</p> <p>2018-01-01</p> <p>A fundamental electrochemical <span class="hlt">model</span> is developed, describing the capacity fade of C6/Li<span class="hlt">Fe</span>PO4 batteries as a function of calendar time and cycling conditions. At moderate temperatures the capacity losses are mainly attributed to Li immobilization in Solid-Electrolyte-Interface (SEI) layers at the anode surface. The SEI formation <span class="hlt">model</span> presumes the availability of an outer and inner SEI layers. Electron tunneling through the inner SEI layer is regarded as the rate-determining step. The <span class="hlt">model</span> also includes high temperature degradation. At elevated temperatures, iron dissolution from the positive electrode and the subsequent metal sedimentation on the negative electrode influence the capacity loss. The SEI formation on the metal-covered graphite surface is faster than the conventional SEI formation. The <span class="hlt">model</span> predicts that capacity fade during storage is lower than during cycling due to the generation of SEI cracks induced by the volumetric changes during (dis)charging. The <span class="hlt">model</span> has been <span class="hlt">validated</span> by cycling and calendar aging experiments and shows that the capacity loss during storage depends on the storage time, the State-of-Charge (SoC), and temperature. The capacity losses during cycling depend on the cycling current, cycling time, temperature and cycle number. All these dependencies can be explained by the single <span class="hlt">model</span> presented in this paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22911248','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22911248"><span>Di/mono-nuclear iron(I)/(II) complexes as functional <span class="hlt">models</span> for the 2<span class="hlt">Fe</span>2S subunit and distal <span class="hlt">Fe</span> moiety of the active site of [<span class="hlt">FeFe</span>] hydrogenases: protonations, molecular structures and electrochemical properties.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gao, Shang; Fan, Jiangli; Sun, Shiguo; Song, Fengling; Peng, Xiaojun; Duan, Qian; Jiang, Dayong; Liang, Qingcheng</p> <p>2012-10-21</p> <p>Di/mono-nuclear iron(I)/(II) complexes containing conjugated and electron-withdrawing S-to-S linkers, [{(μ-S)(2)(C(4)N(2)H(2))}<span class="hlt">Fe</span>(2)(CO)(6)] (1), [{(μ-S)(2)(C(4)N(2)H(2))}<span class="hlt">Fe</span>(2)(CO)(5)(PMe(3))] (1P), and [{(μ-S)(2)(C(4)N(2)H(2))}<span class="hlt">Fe</span>(CO)(2)(PMe(3))(2)] (2) were prepared as biomimetic <span class="hlt">models</span> for the 2<span class="hlt">Fe</span>2S subunit and distal <span class="hlt">Fe</span> moiety of the active site of [<span class="hlt">FeFe</span>] hydrogenases. The N atoms in the heterocyclic pyrazines of 1 and 2 were protonated in the presence of proton acid to generate one and two hydrides, [1(NH)](+) CF(3)SO(3)(-), [2(NH)](+) CF(3)SO(3)(-), and [2(NH)(2)](2+) (CF(3)SO(3)(-))(2), respectively. The protonation processes were evidenced by in situ IR and NMR spectroscopy. The molecular structures of the protonated species [1(NH)](+) CF(3)SO(3)(-) and [2(NH)(2)](2+) (CF(3)SO(3)(-))(2) together with their originating complexes and , and the mono-PMe(3) substituted diiron complex were identified by X-ray crystallography. The IR and single-crystal analysis data all suggested that the electron-withdrawing bridge, pyrazine, led to decreased electron density at the <span class="hlt">Fe</span> centers of the <span class="hlt">model</span> complexes, which was consistent with the electrochemical studies. The cyclic voltammograms indicated that complex exhibited a low primary reduction potential at -1.17 V vs. Fc-Fc(+) with a 270 mV positive shift compared with that of the benzene-1,2-dithiolate (bdt) bridged analogue [(μ-bdt)<span class="hlt">Fe</span>(2)(CO)(6)]. Under the weak acid conditions, complexes 1 and 2 could electrochemically catalyze the proton reduction. More interestingly, the mononuclear ferrous complex 2 showed two catalytic peaks during the formation of hydrogen, confirming its potential as a catalyst for hydrogen production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28287233','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28287233"><span>Dithiolato-bridged nickel-iron complexes as <span class="hlt">models</span> for the active site of [Ni<span class="hlt">Fe</span>]-hydrogenases.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Song, Li-Cheng; Yang, Xi-Yue; Cao, Meng; Gao, Xiu-Yun; Liu, Bei-Bei; Zhu, Liang; Jiang, Feng</p> <p>2017-03-30</p> <p>The structural and functional <span class="hlt">modeling</span> of the active site of [Ni<span class="hlt">Fe</span>]-hydrogenases has been proved to be challenging to a great extent. Herein, we report the synthesis, structures, and some properties of the Ni<span class="hlt">Fe</span>-based dicarbonyl, terminal hydride, and μ-hydroxo <span class="hlt">models</span> for the active site of [Ni<span class="hlt">Fe</span>]-hydrogenases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4510704','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4510704"><span>Synthetic Active Site <span class="hlt">Model</span> of the [Ni<span class="hlt">Fe</span>Se] Hydrogenase</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wombwell, Claire; Reisner, Erwin</p> <p>2015-01-01</p> <p>A dinuclear synthetic <span class="hlt">model</span> of the [Ni<span class="hlt">Fe</span>Se] hydrogenase active site and a structural, spectroscopic and electrochemical analysis of this complex is reported. [Ni<span class="hlt">Fe</span>(‘S2Se2’)(CO)3] (H2‘S2Se2’=1,2-bis(2-thiabutyl-3,3-dimethyl-4-selenol)benzene) has been synthesized by reacting the nickel selenolate complex [Ni(‘S2Se2’)] with [<span class="hlt">Fe</span>(CO)3bda] (bda=benzylideneacetone). X-ray crystal structure analysis confirms that [Ni<span class="hlt">Fe</span>(‘S2Se2’)(CO)3] mimics the key structural features of the enzyme active site, including a doubly bridged heterobimetallic nickel and iron center with a selenolate terminally coordinated to the nickel center. Comparison of [Ni<span class="hlt">Fe</span>(‘S2Se2’)(CO)3] with the previously reported thiolate analogue [Ni<span class="hlt">Fe</span>(‘S4’)(CO)3] (H2‘S4’=H2xbsms=1,2-bis(4-mercapto-3,3-dimethyl-2-thiabutyl)benzene) showed that the selenolate groups in [Ni<span class="hlt">Fe</span>(‘S2Se2’)(CO)3] give lower carbonyl stretching frequencies in the IR spectrum. Electrochemical studies of [Ni<span class="hlt">Fe</span>(‘S2Se2’)(CO)3] and [Ni<span class="hlt">Fe</span>(‘S4’)(CO)3] demonstrated that both complexes do not operate as homogenous H2 evolution catalysts, but are precursors to a solid deposit on an electrode surface for H2 evolution catalysis in organic and aqueous solution. PMID:25847470</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3196751','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3196751"><span>Sensitivity and ex vivo <span class="hlt">validation</span> of finite element <span class="hlt">models</span> of the domestic pig cranium</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bright, Jen A; Rayfield, Emily J</p> <p>2011-01-01</p> <p>A finite element (<span class="hlt">FE</span>) <span class="hlt">validation</span> and sensitivity study was undertaken on a modern domestic pig cranium. Bone strain data were collected ex vivo from strain gauges, and compared with results from specimen-specific <span class="hlt">FE</span> <span class="hlt">models</span>. An isotropic, homogeneous <span class="hlt">model</span> was created, then input parameters were altered to investigate <span class="hlt">model</span> sensitivity. Heterogeneous, isotropic <span class="hlt">models</span> investigated the effects of a constant-thickness, stiffer outer layer (representing cortical bone) atop a more compliant interior (representing cancellous bone). Loading direction and placement of strain gauges were also varied, and the use of 2D membrane elements at strain gauge locations as a method of projecting 3D <span class="hlt">model</span> strains into the plane of the gauge was investigated. The <span class="hlt">models</span> correctly estimate the loading conditions of the experiment, yet at some locations fail to reproduce correct principal strain magnitudes, and hence strain ratios. Principal strain orientations are predicted well. The initial <span class="hlt">model</span> was too stiff by approximately an order of magnitude. Introducing a compliant interior reported strain magnitudes more similar to the ex vivo results without notably affecting strain orientations, ratios or contour patterns, suggesting that this simple heterogeneity was the equivalent of reducing the overall stiffness of the <span class="hlt">model</span>. <span class="hlt">Models</span> were generally insensitive to moderate changes in loading direction or strain gauge placement, except in the squamosal portion of the zygomatic arch. The use of membrane elements made negligible differences to the reported strains. The <span class="hlt">models</span> therefore seem most sensitive to changes in material properties, and suggest that failure to <span class="hlt">model</span> local heterogeneity in material properties and structure of the bone may be responsible for discrepancies between the experimental and <span class="hlt">model</span> results. This is partially attributable to a lack of resolution in the CT scans from which the <span class="hlt">model</span> was built, and partially due to an absence of detailed material properties data</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JaJAP..57a3001H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JaJAP..57a3001H"><span>Interface perpendicular magnetic anisotropy in ultrathin Ta/Ni<span class="hlt">Fe</span>/Pt layered structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirayama, Shigeyuki; Kasai, Shinya; Mitani, Seiji</p> <p>2018-01-01</p> <p>Interface perpendicular magnetic anisotropy (PMA) in ultrathin Ta/Ni<span class="hlt">Fe</span>/Pt layered structures was investigated through magnetization measurements. Ta/Ni<span class="hlt">Fe</span>/Pt films with Ni<span class="hlt">Fe</span> layer thickness (t) values of 2 nm or more showed typical in-plane magnetization curves, which was presumably due to the dominant contribution of the shape magnetic anisotropy. The thickness dependence of the saturation magnetization of the entire Ni<span class="hlt">Fe</span> layer (M s) was well analyzed using the so-called dead-layer <span class="hlt">model</span>, showing that the magnetically active part of the Ni<span class="hlt">Fe</span> layer has saturation magnetization (M\\text{s}\\text{act}) independent of t and comparable to the bulk value. In the perpendicular direction, the saturation field H k was found to clearly decrease with decreasing t, while the effective field of shape magnetic anisotropy due to the active Ni<span class="hlt">Fe</span> saturation magnetization M\\text{s}\\text{act} should be independent of t. These observations show that there exists interface PMA in the layered structures. The interface PMA energy density was determined to be ∼0.17 erg/cm2 using the dead-layer <span class="hlt">model</span>. Motivated by the correlation observed between M s and H k, we also attempted to interpret the experimental results using an alternative approach beyond the dead-layer <span class="hlt">model</span>; however, it gives only implications on the incomplete <span class="hlt">validity</span> of the dead-layer <span class="hlt">model</span> and no better understanding.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3979640','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3979640"><span>Contact-coupled impact of slender rods: analysis and experimental <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tibbitts, Ira B.; Kakarla, Deepika; Siskey, Stephanie; Ochoa, Jorge A.; Ong, Kevin L.; Brannon, Rebecca M.</p> <p>2013-01-01</p> <p>To <span class="hlt">validate</span> <span class="hlt">models</span> of contact mechanics in low speed structural impact, slender rods were impacted in a drop tower, and measurements of the contact and vibration were compared to analytical and finite element (<span class="hlt">FE</span>) <span class="hlt">models</span>. The contact area was recorded using a novel thin-film transfer technique, and the contact duration was measured using electrical continuity. Strain gages recorded the vibratory strain in one rod, and a laser Doppler vibrometer measured speed. The experiment was <span class="hlt">modeled</span> analytically on a one-dimensional spatial domain using a quasi-static Hertzian contact law and a system of delay differential equations. The three-dimensional <span class="hlt">FE</span> <span class="hlt">model</span> used hexahedral elements, a penalty contact algorithm, and explicit time integration. A small submodel taken from the initial global <span class="hlt">FE</span> <span class="hlt">model</span> economically refined the analysis in the small contact region. Measured contact areas were within 6% of both models’ predictions, peak speeds within 2%, cyclic strains within 12 με (RMS value), and contact durations within 2 μs. The global <span class="hlt">FE</span> <span class="hlt">model</span> and the measurements revealed small disturbances, not predicted by the analytical <span class="hlt">model</span>, believed to be caused by interactions of the non-planar stress wavefront with the rod’s ends. The accuracy of the predictions for this simple test, as well as the versatility of the diagnostic tools, <span class="hlt">validates</span> the theoretical and computational <span class="hlt">models</span>, corroborates instrument calibration, and establishes confidence that the same methods may be used in experimental and computational study of contact mechanics during impact of more complicated structures. Recommendations are made for applying the methods to a particular biomechanical problem: the edge-loading of a loose prosthetic hip joint which can lead to premature wear and prosthesis failure. PMID:24729630</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25847470','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25847470"><span>Synthetic Active Site <span class="hlt">Model</span> of the [Ni<span class="hlt">Fe</span>Se] Hydrogenase.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wombwell, Claire; Reisner, Erwin</p> <p>2015-05-26</p> <p>A dinuclear synthetic <span class="hlt">model</span> of the [Ni<span class="hlt">Fe</span>Se] hydrogenase active site and a structural, spectroscopic and electrochemical analysis of this complex is reported. [Ni<span class="hlt">Fe</span>('S2Se2')(CO)3] (H2'S2Se2' = 1,2-bis(2-thiabutyl-3,3-dimethyl-4-selenol)benzene) has been synthesized by reacting the nickel selenolate complex [Ni('S2Se2')] with [<span class="hlt">Fe</span>(CO)3bda] (bda = benzylideneacetone). X-ray crystal structure analysis confirms that [Ni<span class="hlt">Fe</span>('S2Se2')(CO)3] mimics the key structural features of the enzyme active site, including a doubly bridged heterobimetallic nickel and iron center with a selenolate terminally coordinated to the nickel center. Comparison of [Ni<span class="hlt">Fe</span>('S2Se2')(CO)3] with the previously reported thiolate analogue [Ni<span class="hlt">Fe</span>('S4')(CO)3] (H2'S4' = H2xbsms = 1,2-bis(4-mercapto-3,3-dimethyl-2-thiabutyl)benzene) showed that the selenolate groups in [Ni<span class="hlt">Fe</span>('S2Se2')(CO)3] give lower carbonyl stretching frequencies in the IR spectrum. Electrochemical studies of [Ni<span class="hlt">Fe</span>('S2Se2')(CO)3] and [Ni<span class="hlt">Fe</span>('S4')(CO)3] demonstrated that both complexes do not operate as homogenous H2 evolution catalysts, but are precursors to a solid deposit on an electrode surface for H2 evolution catalysis in organic and aqueous solution. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA559825','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA559825"><span>Parameterization and <span class="hlt">Validation</span> of an Integrated Electro-Thermal LFP Battery <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-01-01</p> <p>integrated electro- thermal <span class="hlt">model</span> for an A123 26650 Li<span class="hlt">Fe</span>PO4 battery is presented. The electrical dynamics of the cell are described by an equivalent...the parameterization of an integrated electro-thermal <span class="hlt">model</span> for an A123 26650 Li<span class="hlt">Fe</span>PO4 battery is presented. The electrical dynamics of the cell are...the average of the charge and discharge curves taken at very low current (C/20), since the Li<span class="hlt">Fe</span>PO4 cell chemistry is known to yield a hysteresis effect</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70047000','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70047000"><span>Ground-water <span class="hlt">models</span>: <span class="hlt">Validate</span> or invalidate</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bredehoeft, J.D.; Konikow, Leonard F.</p> <p>1993-01-01</p> <p>The word <span class="hlt">validation</span> has a clear meaning to both the scientific community and the general public. Within the scientific community the <span class="hlt">validation</span> of scientific theory has been the subject of philosophical debate. The philosopher of science, Karl Popper, argued that scientific theory cannot be <span class="hlt">validated</span>, only invalidated. Popper’s view is not the only opinion in this debate; however, many scientists today agree with Popper (including the authors). To the general public, proclaiming that a ground-water <span class="hlt">model</span> is <span class="hlt">validated</span> carries with it an aura of correctness that we do not believe many of us who <span class="hlt">model</span> would claim. We can place all the caveats we wish, but the public has its own understanding of what the word implies. Using the word <span class="hlt">valid</span> with respect to <span class="hlt">models</span> misleads the public; verification carries with it similar connotations as far as the public is concerned. Our point is this: using the terms <span class="hlt">validation</span> and verification are misleading, at best. These terms should be abandoned by the ground-water community.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27083097','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27083097"><span>Empirical agreement in <span class="hlt">model</span> <span class="hlt">validation</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jebeile, Julie; Barberousse, Anouk</p> <p>2016-04-01</p> <p>Empirical agreement is often used as an important criterion when assessing the <span class="hlt">validity</span> of scientific <span class="hlt">models</span>. However, it is by no means a sufficient criterion as a <span class="hlt">model</span> can be so adjusted as to fit available data even though it is based on hypotheses whose plausibility is known to be questionable. Our aim in this paper is to investigate into the uses of empirical agreement within the process of <span class="hlt">model</span> <span class="hlt">validation</span>. Copyright © 2015 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1258482-multi-scale-model-dislocation-plasticity-fe-incorporating-temperature-strain-rate-non-schmid-effects','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1258482-multi-scale-model-dislocation-plasticity-fe-incorporating-temperature-strain-rate-non-schmid-effects"><span>A multi-scale <span class="hlt">model</span> of dislocation plasticity in α-<span class="hlt">Fe</span>: Incorporating temperature, strain rate and non-Schmid effects</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Lim, H.; Hale, L. M.; Zimmerman, J. A.; ...</p> <p>2015-01-05</p> <p>In this study, we develop an atomistically informed crystal plasticity finite element (CP-<span class="hlt">FE</span>) <span class="hlt">model</span> for body-centered-cubic (BCC) α-<span class="hlt">Fe</span> that incorporates non-Schmid stress dependent slip with temperature and strain rate effects. Based on recent insights obtained from atomistic simulations, we propose a new constitutive <span class="hlt">model</span> that combines a generalized non-Schmid yield law with aspects from a line tension (LT) <span class="hlt">model</span> for describing activation enthalpy required for the motion of dislocation kinks. Atomistic calculations are conducted to quantify the non-Schmid effects while both experimental data and atomistic simulations are used to assess the temperature and strain rate effects. The parameterized constitutive equationmore » is implemented into a BCC CP-<span class="hlt">FE</span> <span class="hlt">model</span> to simulate plastic deformation of single and polycrystalline <span class="hlt">Fe</span> which is compared with experimental data from the literature. This direct comparison demonstrates that the atomistically informed <span class="hlt">model</span> accurately captures the effects of crystal orientation, temperature and strain rate on the flow behavior of siangle crystal <span class="hlt">Fe</span>. Furthermore, our proposed CP-<span class="hlt">FE</span> <span class="hlt">model</span> exhibits temperature and strain rate dependent flow and yield surfaces in polycrystalline <span class="hlt">Fe</span> that deviate from conventional CP-<span class="hlt">FE</span> <span class="hlt">models</span> based on Schmid's law.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19944526','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19944526"><span>Investigating the mechanism of clofibric acid removal in <span class="hlt">Fe</span>(0)/H2O systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ghauch, Antoine; Abou Assi, Hala; Tuqan, Almuthanna</p> <p>2010-04-15</p> <p>Since the introduction of iron wall technology, the inherent relationship between contaminant removal and iron corrosion has been mostly attributed to electron transfer from the metal body (direct reduction). This thermodynamically founded premise has failed to explain several experimental facts. Recently, a new concept considering adsorption and co-precipitation as fundamental contaminant removal mechanisms was introduced. This consistent concept has faced very skeptic views and necessarily needs experimental <span class="hlt">validation</span>. The present work was the first independent attempt to <span class="hlt">validate</span> the new concept using clofibric acid (CLO) as <span class="hlt">model</span> compound. For this purpose, a powdered <span class="hlt">Fe</span>(0) material (<span class="hlt">Fe</span>(0)) was used in CLO removal experiments under various experimental conditions. Additional experiments were performed with plated <span class="hlt">Fe</span>(0) (m<span class="hlt">Fe</span>(0): <span class="hlt">Fe</span>(0)/Pd(0), <span class="hlt">Fe</span>(0)/Ni(0)) to support the discussion of removal mechanism. Main investigated experimental variables included: abundance of O(2), abundance of iron corrosion products (ICPs) and shaking operations. Results corroborated the concept that quantitative contaminant removal in <span class="hlt">Fe</span>(0)/H(2)O systems occurs within the oxide-film in the vicinity of <span class="hlt">Fe</span>(0). Additionally, mixing type and shaking intensity significantly influenced the extent of CLO removal. More importantly, HPLC/MS revealed that the identity of reaction products depends on the extent of iron corrosion or the abundance of ICPs. The investigation of the CLO/<span class="hlt">Fe</span>(0)/H(2)O system disproved the popular view that direct reduction mediates contaminant removal in the presence of <span class="hlt">Fe</span>(0). 2009 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28291687','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28291687"><span>Structural biomechanics of the craniomaxillofacial skeleton under maximal masticatory loading: Inferences and critical analysis based on a <span class="hlt">validated</span> computational <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pakdel, Amir R; Whyne, Cari M; Fialkov, Jeffrey A</p> <p>2017-06-01</p> <p>The trend towards optimizing stabilization of the craniomaxillofacial skeleton (CMFS) with the minimum amount of fixation required to achieve union, and away from maximizing rigidity, requires a quantitative understanding of craniomaxillofacial biomechanics. This study uses computational <span class="hlt">modeling</span> to quantify the structural biomechanics of the CMFS under maximal physiologic masticatory loading. Using an experimentally <span class="hlt">validated</span> subject-specific finite element (<span class="hlt">FE</span>) <span class="hlt">model</span> of the CMFS, the patterns of stress and strain distribution as a result of physiological masticatory loading were calculated. The trajectories of the stresses were plotted to delineate compressive and tensile regimes over the entire CMFS volume. The lateral maxilla was found to be the primary vertical buttress under maximal bite force loading, with much smaller involvement of the naso-maxillary buttress. There was no evidence that the pterygo-maxillary region is a buttressing structure, counter to classical buttress theory. The stresses at the zygomatic sutures suggest that two-point fixation of zygomatic complex fractures may be sufficient for fixation under bite force loading. The current experimentally <span class="hlt">validated</span> biomechanical <span class="hlt">FE</span> <span class="hlt">model</span> of the CMFS is a practical tool for in silico optimization of current practice techniques and may be used as a foundation for the development of design criteria for future technologies for the treatment of CMFS injury and disease. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25234420','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25234420"><span>A [Ni<span class="hlt">Fe</span>]hydrogenase <span class="hlt">model</span> that catalyses the release of hydrogen from formic acid.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nguyen, Nga T; Mori, Yuki; Matsumoto, Takahiro; Yatabe, Takeshi; Kabe, Ryota; Nakai, Hidetaka; Yoon, Ki-Seok; Ogo, Seiji</p> <p>2014-11-11</p> <p>We report the decomposition of formic acid to hydrogen and carbon dioxide, catalysed by a NiRu complex originally developed as a [Ni<span class="hlt">Fe</span>]hydrogenase <span class="hlt">model</span>. This is the first example of H2 evolution, catalysed by a [Ni<span class="hlt">Fe</span>]hydrogenase <span class="hlt">model</span>, which does not require additional energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH43B2825R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH43B2825R"><span><span class="hlt">Modeling</span> 13.3nm <span class="hlt">Fe</span> XXIII Flare Emissions Using the GOES-R EXIS Instrument</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rook, H.; Thiemann, E.</p> <p>2017-12-01</p> <p>The solar EUV spectrum is dominated by atomic transitions in ionized atoms in the solar atmosphere. As solar flares evolve, plasma temperatures and densities change, influencing abundances of various ions, changing intensities of different EUV wavelengths observed from the sun. Quantifying solar flare spectral irradiance is important for constraining <span class="hlt">models</span> of Earth's atmosphere, improving communications quality, and controlling satellite navigation. However, high time cadence measurements of flare irradiance across the entire EUV spectrum were not available prior to the launch of SDO. The EVE MEGS-A instrument aboard SDO collected 0.1nm EUV spectrum data from 2010 until 2014, when the instrument failed. No current or future instrument is capable of similar high resolution and time cadence EUV observation. This necessitates a full EUV spectrum <span class="hlt">model</span> to study EUV phenomena at Earth. It has been recently demonstrated that one hot flare EUV line, such as the 13.3nm <span class="hlt">Fe</span> XXIII line, can be used to <span class="hlt">model</span> cooler flare EUV line emissions, filling the role of MEGS-A. Since unblended measurements of <span class="hlt">Fe</span> XXIII are typically unavailable, a proxy for the <span class="hlt">Fe</span> XXIII line must be found. In this study, we construct two <span class="hlt">models</span> of this line, first using the GOES 0.1-0.8nm soft x-ray (SXR) channel as the <span class="hlt">Fe</span> XXIII proxy, and second using a physics-based <span class="hlt">model</span> dependent on GOES emission measure and temperature data. We determine that the more sophisticated physics-based <span class="hlt">model</span> shows better agreement with <span class="hlt">Fe</span> XXIII measurements, although the simple proxy <span class="hlt">model</span> also performs well. We also conclude that the high correlation between <span class="hlt">Fe</span> XXIII emissions and the GOES 0.1-0.8nm band is because both emissions tend to peak near the GOES emission measure peak despite large differences in their contribution functions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19058105','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19058105"><span>Research study on neck injury lessening with active head restraint using human body <span class="hlt">FE</span> <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kitagawa, Yuichi; Yasuki, Tsuyoshi; Hasegawa, Junji</p> <p>2008-12-01</p> <p>The objective of this study is to examine the effectiveness of the active head restraint system in reducing neck injury risk of car occupants in low-speed rear impacts. A human body <span class="hlt">FE</span> <span class="hlt">model</span> "THUMS" was used to simulate head and neck kinematics of the occupant and to evaluate loading to the neck. Joint capsule strain was calculated to predict neck injury risk as well as NIC. The <span class="hlt">validity</span> of the <span class="hlt">model</span> was confirmed comparing its mechanical responses to those in human subjects in the literatures. Seat <span class="hlt">FE</span> <span class="hlt">models</span> were also prepared representing one with a fixed head restraint and the other one with an active head restraint system. The active head restraint system was designed to move the head restraint forward and upward when the lower unit was lower unit was loaded by the pelvis. Rear impact simulations were performed assuming a triangular acceleration pulse at a delta-V of 25 km/h. The <span class="hlt">model</span> reproduced similar head and neck motions to those measured in the human volunteer test, except for active muscular responses. The calculated joint capsule strain also showed a good match with those of PMHS tests in the literature. A rear-impact simulation was conducted using the <span class="hlt">model</span> with the fixed head restraint. The result revealed that NIC was strongly correlated with the relative acceleration between the head and the torso and that its maximum peak appeared when the head contacted the head restraint. It was also found that joint capsule strain grew in later timing synchronizing with the relative displacement. Another simulation with the active head restraint system showed that both NIC and joint capsule strain were lowered owing to the forward and upward motion of the head restraint. A close investigation of the vertebral motion indicated that the active head restraint reduced the magnitude of shear deformation in the facet joint, which contributed to the strain growth in the fixed head restraint case. Rear-impact simulations were conducted using a human body <span class="hlt">FE</span> <span class="hlt">model</span>, THUMS</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2000/0401/pdf/of00-401.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2000/0401/pdf/of00-401.pdf"><span>Towards policy relevant environmental <span class="hlt">modeling</span>: contextual <span class="hlt">validity</span> and pragmatic <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Miles, Scott B.</p> <p>2000-01-01</p> <p>"What makes for a good <span class="hlt">model</span>?" In various forms, this question is a question that, undoubtedly, many people, businesses, and institutions ponder with regards to their particular domain of <span class="hlt">modeling</span>. One particular domain that is wrestling with this question is the multidisciplinary field of environmental <span class="hlt">modeling</span>. Examples of environmental <span class="hlt">models</span> range from <span class="hlt">models</span> of contaminated ground water flow to the economic impact of natural disasters, such as earthquakes. One of the distinguishing claims of the field is the relevancy of environmental <span class="hlt">modeling</span> to policy and environment-related decision-making in general. A pervasive view by both scientists and decision-makers is that a "good" <span class="hlt">model</span> is one that is an accurate predictor. Thus, determining whether a <span class="hlt">model</span> is "accurate" or "correct" is done by comparing <span class="hlt">model</span> output to empirical observations. The expected outcome of this process, usually referred to as "<span class="hlt">validation</span>" or "ground truthing," is a stamp on the <span class="hlt">model</span> in question of "<span class="hlt">valid</span>" or "not <span class="hlt">valid</span>" that serves to indicate whether or not the <span class="hlt">model</span> will be reliable before it is put into service in a decision-making context. In this paper, I begin by elaborating on the prevailing view of <span class="hlt">model</span> <span class="hlt">validation</span> and why this view must change. Drawing from concepts coming out of the studies of science and technology, I go on to propose a contextual view of <span class="hlt">validity</span> that can overcome the problems associated with "ground truthing" <span class="hlt">models</span> as an indicator of <span class="hlt">model</span> goodness. The problem of how we talk about and determine <span class="hlt">model</span> <span class="hlt">validity</span> has much to do about how we perceive the utility of environmental <span class="hlt">models</span>. In the remainder of the paper, I argue that we should adopt ideas of pragmatism in judging what makes for a good <span class="hlt">model</span> and, in turn, developing good <span class="hlt">models</span>. From such a perspective of <span class="hlt">model</span> goodness, good environmental <span class="hlt">models</span> should facilitate communication, convey—not bury or "eliminate"—uncertainties, and, thus, afford the active building of consensus decisions, instead</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24402840','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24402840"><span>Synthesis and reactivity of mononuclear iron <span class="hlt">models</span> of [<span class="hlt">Fe</span>]-hydrogenase that contain an acylmethylpyridinol ligand.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, Bowen; Chen, Dafa; Hu, Xile</p> <p>2014-02-03</p> <p>[<span class="hlt">Fe</span>]-hydrogenase has a single iron-containing active site that features an acylmethylpyridinol ligand. This unique ligand environment had yet to be reproduced in synthetic <span class="hlt">models</span>; however the synthesis and reactivity of a new class of small molecule mimics of [<span class="hlt">Fe</span>]-hydrogenase in which a mono-iron center is ligated by an acylmethylpyridinol ligand has now been achieved. Key to the preparation of these <span class="hlt">model</span> compounds is the successful C-O cleavage of an alkyl ether moiety to form the desired pyridinol ligand. Reaction of solvated complex [(2-CH2CO-6-HOC5H3N)<span class="hlt">Fe</span>(CO)2(CH3CN)2](+)(BF4)(-) with thiols or thiophenols in the presence of NEt3 yielded 5-coordinate iron thiolate complexes. Further derivation produced complexes [(2-CH2CO-6-HOC5H3N)<span class="hlt">Fe</span>(CO)2(SCH2CH2OH)] and [(2-CH2CO-6-HOC5H3N)<span class="hlt">Fe</span>(CO)2(CH3COO)], which can be regarded as <span class="hlt">models</span> of <span class="hlt">Fe</span>GP cofactors of [<span class="hlt">Fe</span>]-hydrogenase extracted by 2-mercaptoethanol and acetic acid, respectively. When the derivative complexes were treated with HBF4 ⋅Et2O, the solvated complex was regenerated by protonation of the thiolate ligands. The reactivity of several <span class="hlt">models</span> with CO, isocyanide, cyanide, and H2 was also investigated. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=validation&id=EJ1028290','ERIC'); return false;" href="https://eric.ed.gov/?q=validation&id=EJ1028290"><span>Teaching "Instant Experience" with Graphical <span class="hlt">Model</span> <span class="hlt">Validation</span> Techniques</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ekstrøm, Claus Thorn</p> <p>2014-01-01</p> <p>Graphical <span class="hlt">model</span> <span class="hlt">validation</span> techniques for linear normal <span class="hlt">models</span> are often used to check the assumptions underlying a statistical <span class="hlt">model</span>. We describe an approach to provide "instant experience" in looking at a graphical <span class="hlt">model</span> <span class="hlt">validation</span> plot, so it becomes easier to <span class="hlt">validate</span> if any of the underlying assumptions are violated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090023167','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090023167"><span>Development and <span class="hlt">Validation</span> of a <span class="hlt">Model</span> for Hydrogen Reduction of JSC-1A</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hegde, U.; Balasubramaniam, R.; Gokoglu, S.</p> <p>2009-01-01</p> <p>Hydrogen reduction of lunar regolith has been proposed as a viable technology for oxygen production on the moon. Hydrogen reduces <span class="hlt">Fe</span>O present in the lunar regolith to form metallic iron and water. The water may be electrolyzed to recycle the hydrogen and produce oxygen. Depending upon the regolith composition, <span class="hlt">Fe</span>O may be bound to TiO2 as ilmenite or it may be dispersed in glassy substrates. Some testing of hydrogen reduction has been conducted with Apollo-returned lunar regolith samples. However, due to the restricted amount of lunar material available for testing, detailed understanding and <span class="hlt">modeling</span> of the reduction process in regolith have not yet been developed. As a step in this direction, hydrogen reduction studies have been carried out in more detail with lunar regolith simulants such as JSC-1A by NASA and other organizations. While JSC-1A has some similarities with lunar regolith, it does not duplicate the wide variety of regolith types on the moon, for example, it contains almost no ilmenite. Nonetheless, it is a good starting point for developing an understanding of the hydrogen reduction process with regolith-like material. In this paper, a <span class="hlt">model</span> utilizing a shrinking core formulation coupled with the reactor flow is described and <span class="hlt">validated</span> against experimental data on hydrogen reduction of JSC-1A.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22541961','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22541961"><span>Statistical <span class="hlt">validation</span> of normal tissue complication probability <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Cheng-Jian; van der Schaaf, Arjen; Van't Veld, Aart A; Langendijk, Johannes A; Schilstra, Cornelis</p> <p>2012-09-01</p> <p>To investigate the applicability and value of double cross-<span class="hlt">validation</span> and permutation tests as established statistical approaches in the <span class="hlt">validation</span> of normal tissue complication probability (NTCP) <span class="hlt">models</span>. A penalized regression method, LASSO (least absolute shrinkage and selection operator), was used to build NTCP <span class="hlt">models</span> for xerostomia after radiation therapy treatment of head-and-neck cancer. <span class="hlt">Model</span> assessment was based on the likelihood function and the area under the receiver operating characteristic curve. Repeated double cross-<span class="hlt">validation</span> showed the uncertainty and instability of the NTCP <span class="hlt">models</span> and indicated that the statistical significance of <span class="hlt">model</span> performance can be obtained by permutation testing. Repeated double cross-<span class="hlt">validation</span> and permutation tests are recommended to <span class="hlt">validate</span> NTCP <span class="hlt">models</span> before clinical use. Copyright © 2012 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23137095','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23137095"><span>Repositioning the knee joint in human body <span class="hlt">FE</span> <span class="hlt">models</span> using a graphics-based technique.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jani, Dhaval; Chawla, Anoop; Mukherjee, Sudipto; Goyal, Rahul; Vusirikala, Nataraju; Jayaraman, Suresh</p> <p>2012-01-01</p> <p>Human body finite element <span class="hlt">models</span> (<span class="hlt">FE</span>-HBMs) are available in standard occupant or pedestrian postures. There is a need to have <span class="hlt">FE</span>-HBMs in the same posture as a crash victim or to be configured in varying postures. Developing <span class="hlt">FE</span> <span class="hlt">models</span> for all possible positions is not practically viable. The current work aims at obtaining a posture-specific human lower extremity <span class="hlt">model</span> by reconfiguring an existing one. A graphics-based technique was developed to reposition the lower extremity of an <span class="hlt">FE</span>-HBM by specifying the flexion-extension angle. Elements of the <span class="hlt">model</span> were segregated into rigid (bones) and deformable components (soft tissues). The bones were rotated about the flexion-extension axis followed by rotation about the longitudinal axis to capture the twisting of the tibia. The desired knee joint movement was thus achieved. Geometric heuristics were then used to reposition the skin. A mapping defined over the space between bones and the skin was used to regenerate the soft tissues. Mesh smoothing was then done to augment mesh quality. The developed method permits control over the kinematics of the joint and maintains the initial mesh quality of the <span class="hlt">model</span>. For some critical areas (in the joint vicinity) where element distortion is large, mesh smoothing is done to improve mesh quality. A method to reposition the knee joint of a human body <span class="hlt">FE</span> <span class="hlt">model</span> was developed. Repositions of a <span class="hlt">model</span> from 9 degrees of flexion to 90 degrees of flexion in just a few seconds without subjective interventions was demonstrated. Because the mesh quality of the repositioned <span class="hlt">model</span> was maintained to a predefined level (typically to the level of a well-made <span class="hlt">model</span> in the initial configuration), the <span class="hlt">model</span> was suitable for subsequent simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29414839','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29414839"><span>Mechanism-Based <span class="hlt">FE</span> Simulation of Tool Wear in Diamond Drilling of SiCp/Al Composites.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xiang, Junfeng; Pang, Siqin; Xie, Lijing; Gao, Feinong; Hu, Xin; Yi, Jie; Hu, Fang</p> <p>2018-02-07</p> <p>The aim of this work is to analyze the micro mechanisms underlying the wear of macroscale tools during diamond machining of SiC p /Al6063 composites and to develop the mechanism-based diamond wear <span class="hlt">model</span> in relation to the dominant wear behaviors. During drilling, high volume fraction SiC p /Al6063 composites containing Cu, the dominant wear mechanisms of diamond tool involve thermodynamically activated physicochemical wear due to diamond-graphite transformation catalyzed by Cu in air atmosphere and mechanically driven abrasive wear due to high-frequency scrape of hard SiC reinforcement on tool surface. An analytical diamond wear <span class="hlt">model</span>, coupling Usui abrasive wear <span class="hlt">model</span> and Arrhenius extended graphitization wear <span class="hlt">model</span> was proposed and implemented through a user-defined subroutine for tool wear estimates. Tool wear estimate in diamond drilling of SiC p /Al6063 composites was achieved by incorporating the combined abrasive-chemical tool wear subroutine into the coupled thermomechanical <span class="hlt">FE</span> <span class="hlt">model</span> of 3D drilling. The developed drilling <span class="hlt">FE</span> <span class="hlt">model</span> for reproducing diamond tool wear was <span class="hlt">validated</span> for feasibility and reliability by comparing numerically simulated tool wear morphology and experimentally observed results after drilling a hole using brazed polycrystalline diamond (PCD) and chemical vapor deposition (CVD) diamond coated tools. A fairly good agreement of experimental and simulated results in cutting forces, chip and tool wear morphologies demonstrates that the developed 3D drilling <span class="hlt">FE</span> <span class="hlt">model</span>, combined with a subroutine for diamond tool wear estimate can provide a more accurate analysis not only in cutting forces and chip shape but also in tool wear behavior during drilling SiC p /Al6063 composites. Once <span class="hlt">validated</span> and calibrated, the developed diamond tool wear <span class="hlt">model</span> in conjunction with other machining <span class="hlt">FE</span> <span class="hlt">models</span> can be easily extended to the investigation of tool wear evolution with various diamond tool geometries and other machining processes in cutting different</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5848949','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5848949"><span>Mechanism-Based <span class="hlt">FE</span> Simulation of Tool Wear in Diamond Drilling of SiCp/Al Composites</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xiang, Junfeng; Pang, Siqin; Xie, Lijing; Gao, Feinong; Hu, Xin; Yi, Jie; Hu, Fang</p> <p>2018-01-01</p> <p>The aim of this work is to analyze the micro mechanisms underlying the wear of macroscale tools during diamond machining of SiCp/Al6063 composites and to develop the mechanism-based diamond wear <span class="hlt">model</span> in relation to the dominant wear behaviors. During drilling, high volume fraction SiCp/Al6063 composites containing Cu, the dominant wear mechanisms of diamond tool involve thermodynamically activated physicochemical wear due to diamond-graphite transformation catalyzed by Cu in air atmosphere and mechanically driven abrasive wear due to high-frequency scrape of hard SiC reinforcement on tool surface. An analytical diamond wear <span class="hlt">model</span>, coupling Usui abrasive wear <span class="hlt">model</span> and Arrhenius extended graphitization wear <span class="hlt">model</span> was proposed and implemented through a user-defined subroutine for tool wear estimates. Tool wear estimate in diamond drilling of SiCp/Al6063 composites was achieved by incorporating the combined abrasive-chemical tool wear subroutine into the coupled thermomechanical <span class="hlt">FE</span> <span class="hlt">model</span> of 3D drilling. The developed drilling <span class="hlt">FE</span> <span class="hlt">model</span> for reproducing diamond tool wear was <span class="hlt">validated</span> for feasibility and reliability by comparing numerically simulated tool wear morphology and experimentally observed results after drilling a hole using brazed polycrystalline diamond (PCD) and chemical vapor deposition (CVD) diamond coated tools. A fairly good agreement of experimental and simulated results in cutting forces, chip and tool wear morphologies demonstrates that the developed 3D drilling <span class="hlt">FE</span> <span class="hlt">model</span>, combined with a subroutine for diamond tool wear estimate can provide a more accurate analysis not only in cutting forces and chip shape but also in tool wear behavior during drilling SiCp/Al6063 composites. Once <span class="hlt">validated</span> and calibrated, the developed diamond tool wear <span class="hlt">model</span> in conjunction with other machining <span class="hlt">FE</span> <span class="hlt">models</span> can be easily extended to the investigation of tool wear evolution with various diamond tool geometries and other machining processes in cutting different workpiece</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1238750-irradiation-enhanced-precipitation-model-fecral-alloys','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1238750-irradiation-enhanced-precipitation-model-fecral-alloys"><span>Irradiation-enhanced α' precipitation in <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Edmondson, Philip D.; Briggs, Samuel A.; Yamamoto, Yukinori; ...</p> <p>2016-02-17</p> <p>We have irradiated the <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys with varying compositions (<span class="hlt">Fe</span>(10–18)Cr(10–6)Al at.%) with a neutron at ~ 320 to damage levels of ~ 7 displacements per atom (dpa) to investigate the compositional influence on the formation of irradiation-induced Cr-rich α' precipitates using atom probe tomography. In all alloys, significant number densities of these precipitates were observed. Cluster compositions were investigated and it was found that the average cluster Cr content ranged between 51.1 and 62.5 at.% dependent on initial compositions. Furthermore, this is significantly lower than the Cr-content of α' in binary <span class="hlt">Fe</span>Cr alloys. As a result, significant partitioning ofmore » the Al from the α' precipitates was also observed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10170E..1UK','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10170E..1UK"><span>Nonlinear dispersion effects in elastic plates: numerical <span class="hlt">modelling</span> and <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kijanka, Piotr; Radecki, Rafal; Packo, Pawel; Staszewski, Wieslaw J.; Uhl, Tadeusz; Leamy, Michael J.</p> <p>2017-04-01</p> <p>Nonlinear features of elastic wave propagation have attracted significant attention recently. The particular interest herein relates to complex wave-structure interactions, which provide potential new opportunities for feature discovery and identification in a variety of applications. Due to significant complexity associated with wave propagation in nonlinear media, numerical <span class="hlt">modeling</span> and simulations are employed to facilitate design and development of new measurement, monitoring and characterization systems. However, since very high spatio- temporal accuracy of numerical <span class="hlt">models</span> is required, it is critical to evaluate their spectral properties and tune discretization parameters for compromise between accuracy and calculation time. Moreover, nonlinearities in structures give rise to various effects that are not present in linear systems, e.g. wave-wave interactions, higher harmonics generation, synchronism and | recently reported | shifts to dispersion characteristics. This paper discusses local computational <span class="hlt">model</span> based on a new HYBRID approach for wave propagation in nonlinear media. The proposed approach combines advantages of the Local Interaction Simulation Approach (LISA) and Cellular Automata for Elastodynamics (CAFE). The methods are investigated in the context of their accuracy for predicting nonlinear wavefields, in particular shifts to dispersion characteristics for finite amplitude waves and secondary wavefields. The results are <span class="hlt">validated</span> against Finite Element (<span class="hlt">FE</span>) calculations for guided waves in copper plate. Critical modes i.e., modes determining accuracy of a <span class="hlt">model</span> at given excitation frequency - are identified and guidelines for numerical <span class="hlt">model</span> parameters are proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4047624','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4047624"><span>Development and <span class="hlt">validation</span> of a computational <span class="hlt">model</span> of the knee joint for the evaluation of surgical treatments for osteoarthritis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mootanah, R.; Imhauser, C.W.; Reisse, F.; Carpanen, D.; Walker, R.W.; Koff, M.F.; Lenhoff, M.W.; Rozbruch, S.R.; Fragomen, A.T.; Dewan, Z.; Kirane, Y.M.; Cheah, Pamela A.; Dowell, J.K.; Hillstrom, H.J.</p> <p>2014-01-01</p> <p>A three-dimensional (3D) knee joint computational <span class="hlt">model</span> was developed and <span class="hlt">validated</span> to predict knee joint contact forces and pressures for different degrees of malalignment. A 3D computational knee <span class="hlt">model</span> was created from high-resolution radiological images to emulate passive sagittal rotation (full-extension to 65°-flexion) and weight acceptance. A cadaveric knee mounted on a six-degree-of-freedom robot was subjected to matching boundary and loading conditions. A ligament-tuning process minimised kinematic differences between the robotically loaded cadaver specimen and the finite element (<span class="hlt">FE</span>) <span class="hlt">model</span>. The <span class="hlt">model</span> was <span class="hlt">validated</span> by measured intra-articular force and pressure measurements. Percent full scale error between EE-predicted and in vitro-measured values in the medial and lateral compartments were 6.67% and 5.94%, respectively, for normalised peak pressure values, and 7.56% and 4.48%, respectively, for normalised force values. The knee <span class="hlt">model</span> can accurately predict normalised intra-articular pressure and forces for different loading conditions and could be further developed for subject-specific surgical planning. PMID:24786914</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA033302','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA033302"><span>Turbine Engine Mathematical <span class="hlt">Model</span> <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1976-12-01</p> <p>AEDC-TR-76-90 ~Ec i ? Z985 TURBINE ENGINE MATHEMATICAL <span class="hlt">MODEL</span> <span class="hlt">VALIDATION</span> ENGINE TEST FACILITY ARNOLD ENGINEERING DEVELOPMENT CENTER AIR FORCE...i f n e c e s e a ~ ~ d i den t i f y by b l ock number) YJI01-GE-100 engine turbine engines mathematical <span class="hlt">models</span> computations mathematical...report presents and discusses the results of an investigation to develop a rationale and technique for the <span class="hlt">validation</span> of turbine engine steady-state</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1342837','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1342837"><span>A physics-based crystallographic <span class="hlt">modeling</span> framework for describing the thermal creep behavior of <span class="hlt">Fe</span>-Cr alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wen, Wei; Capolungo, Laurent; Patra, Anirban</p> <p></p> <p>This Report addresses the Milestone M2MS-16LA0501032 of NEAMS Program (“Develop hardening <span class="hlt">model</span> for <span class="hlt">Fe</span>CrAl cladding), with a deadline of 09/30/2016. Here we report a constitutive law for thermal creep of <span class="hlt">Fe</span>CrAl. This Report adds to and complements the one for Milestone M3MS-16LA0501034 (“Interface hardening <span class="hlt">models</span> with MOOSE-BISON”), where we presented a hardening law for irradiated <span class="hlt">Fe</span>CrAl. The last component of our polycrystal-based constitutive behavior, namely, an irradiation creep <span class="hlt">model</span> for <span class="hlt">Fe</span>CrAl, will be developed as part of the FY17 Milestones, and the three regimes will be coupled and interfaced with MOOSE-BISON.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AtmRe.197....1T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AtmRe.197....1T"><span>Global precipitation measurements for <span class="hlt">validating</span> climate <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tapiador, F. J.; Navarro, A.; Levizzani, V.; García-Ortega, E.; Huffman, G. J.; Kidd, C.; Kucera, P. A.; Kummerow, C. D.; Masunaga, H.; Petersen, W. A.; Roca, R.; Sánchez, J.-L.; Tao, W.-K.; Turk, F. J.</p> <p>2017-11-01</p> <p>The advent of global precipitation data sets with increasing temporal span has made it possible to use them for <span class="hlt">validating</span> climate <span class="hlt">models</span>. In order to fulfill the requirement of global coverage, existing products integrate satellite-derived retrievals from many sensors with direct ground observations (gauges, disdrometers, radars), which are used as reference for the satellites. While the resulting product can be deemed as the best-available source of quality <span class="hlt">validation</span> data, awareness of the limitations of such data sets is important to avoid extracting wrong or unsubstantiated conclusions when assessing climate <span class="hlt">model</span> abilities. This paper provides guidance on the use of precipitation data sets for climate research, including <span class="hlt">model</span> <span class="hlt">validation</span> and verification for improving physical parameterizations. The strengths and limitations of the data sets for climate <span class="hlt">modeling</span> applications are presented, and a protocol for quality assurance of both observational databases and <span class="hlt">models</span> is discussed. The paper helps elaborating the recent IPCC AR5 acknowledgment of large observational uncertainties in precipitation observations for climate <span class="hlt">model</span> <span class="hlt">validation</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29701159','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29701159"><span>Beware of external <span class="hlt">validation</span>! - A Comparative Study of Several <span class="hlt">Validation</span> Techniques used in QSAR <span class="hlt">Modelling</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Majumdar, Subhabrata; Basak, Subhash C</p> <p>2018-04-26</p> <p>Proper <span class="hlt">validation</span> is an important aspect of QSAR <span class="hlt">modelling</span>. External <span class="hlt">validation</span> is one of the widely used <span class="hlt">validation</span> methods in QSAR where the <span class="hlt">model</span> is built on a subset of the data and <span class="hlt">validated</span> on the rest of the samples. However, its effectiveness for datasets with a small number of samples but large number of predictors remains suspect. Calculating hundreds or thousands of molecular descriptors using currently available software has become the norm in QSAR research, owing to computational advances in the past few decades. Thus, for n chemical compounds and p descriptors calculated for each molecule, the typical chemometric dataset today has high value of p but small n (i.e. n < p). Motivated by the evidence of inadequacies of external <span class="hlt">validation</span> in estimating the true predictive capability of a statistical <span class="hlt">model</span> in recent literature, this paper performs an extensive and comparative study of this method with several other <span class="hlt">validation</span> techniques. We compared four <span class="hlt">validation</span> methods: leave-one-out, K-fold, external and multi-split <span class="hlt">validation</span>, using statistical <span class="hlt">models</span> built using the LASSO regression, which simultaneously performs variable selection and <span class="hlt">modelling</span>. We used 300 simulated datasets and one real dataset of 95 congeneric amine mutagens for this evaluation. External <span class="hlt">validation</span> metrics have high variation among different random splits of the data, hence are not recommended for predictive QSAR <span class="hlt">models</span>. LOO has the overall best performance among all <span class="hlt">validation</span> methods applied in our scenario. Results from external <span class="hlt">validation</span> are too unstable for the datasets we analyzed. Based on our findings, we recommend using the LOO procedure for <span class="hlt">validating</span> QSAR predictive <span class="hlt">models</span> built on high-dimensional small-sample data. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016htmp.book..493Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016htmp.book..493Z"><span><span class="hlt">Modeling</span> and Recovery of Iron (<span class="hlt">Fe</span>) from Red Mud by Coal Reduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Xiancong; Li, Hongxu; Wang, Lei; Zhang, Lifeng</p> <p></p> <p>Recovery of <span class="hlt">Fe</span> from red mud has been studied using statistically designed experiments. The effects of three factors, namely: reduction temperature, reduction time and proportion of additive on recovery of <span class="hlt">Fe</span> have been investigated. Experiments have been carried out using orthogonal central composite design and factorial design methods. A <span class="hlt">model</span> has been obtained through variance analysis at 92.5% confidence level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.109t3110J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.109t3110J"><span><span class="hlt">Modeling</span> Verwey transition temperature of <span class="hlt">Fe</span>3O4 nanocrystals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Xiao bao; Xiao, Bei bei; Yang, Hong yu; Gu, Xiao yan; Sheng, Hong chao; Zhang, Xing hua</p> <p>2016-11-01</p> <p>The Verwey transition in nanoscale is an important physical property for <span class="hlt">Fe</span>3O4 nanocrystals and has attracted extensive attention in recent years. In this work, an analytic thermodynamic <span class="hlt">model</span> without any adjusting parameters is developed to estimate the size and shape effects on modulating the Verwey transition temperature of <span class="hlt">Fe</span>3O4 nanocrystals. The results show that the Verwey transition temperature reduces with increasing shape parameter λ or decreasing size D. A good agreement between the prediction and the experimental data verified our physical insight that the Verwey transition of <span class="hlt">Fe</span>3O4 can be directly related to the atomic thermal vibration. The results presented in this work will be of benefit to the understanding of the microscopic mechanism of the Verwey transition and the design of future generation switching and memory devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29169090','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29169090"><span>Optimization of <span class="hlt">Fe</span>2+ supplement in anaerobic digestion accounting for the <span class="hlt">Fe</span>-bioavailability.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cai, Yafan; Zhao, Xiaoling; Zhao, Yubin; Wang, Hongliang; Yuan, Xufeng; Zhu, Wanbin; Cui, Zongjun; Wang, Xiaofen</p> <p>2018-02-01</p> <p><span class="hlt">Fe</span> is widely used as an additive in anaerobic digestion, but its bioavailability and the mechanism by which it enhances digestion are unclear. In this study, sequential extraction was used to measure <span class="hlt">Fe</span> bioavailability, while biochemical parameters, kinetics <span class="hlt">model</span> and Q-PCR (fluorescence quantitative PCR) were used to explore its mechanism of stimulation. The results showed that sequential extraction is a suitable method to assess the anaerobic system bioavailability of <span class="hlt">Fe</span>, which is low and fluctuates to a limited extent (1.7 to -3.1wt%), indicating that it would be easy for <span class="hlt">Fe</span> levels to be insufficient. Methane yield increased when the added <span class="hlt">Fe</span> 2+ was 10-500mg/L. Appropriate amounts of <span class="hlt">Fe</span> 2+ accelerated the decomposition of rice straw and facilitated methanogen metabolism, thereby improving reactor performance. The modified Gompertz <span class="hlt">model</span> better fitted the results than the first-order kinetic <span class="hlt">model</span>. Feasibility analysis showed that addition of <span class="hlt">Fe</span> 2+ at ≤50mg/L was suitable. Copyright © 2017. Published by Elsevier Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28831157','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28831157"><span>Composition formulas of <span class="hlt">Fe</span>-based transition metals-metalloid bulk metallic glasses derived from dual-cluster <span class="hlt">model</span> of binary eutectics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Naz, Gul Jabeen; Dong, Dandan; Geng, Yaoxiang; Wang, Yingmin; Dong, Chuang</p> <p>2017-08-22</p> <p>It is known that bulk metallic glasses follow simple composition formulas [cluster](glue atom) 1 or 3 with 24 valence electrons within the framework of the cluster-plus-glue-atom <span class="hlt">model</span>. Though the relevant nearest-neighbor cluster can be readily identified from a devitrification phase, the glue atoms remains poorly defined. The present work is devoted to understanding the composition rule of <span class="hlt">Fe</span>-(B,P,C) based multi-component bulk metallic glasses, by introducing a cluster-based eutectic liquid <span class="hlt">model</span>. This <span class="hlt">model</span> regards a eutectic liquid to be composed of two stable liquids formulated respectively by cluster formulas for ideal metallic glasses from the two eutectic phases. The dual cluster formulas are first established for binary <span class="hlt">Fe</span>-(B,C,P) eutectics: [<span class="hlt">Fe-Fe</span> 14 ]B 2 Fe + [B-B 2 <span class="hlt">Fe</span> 8 ]<span class="hlt">Fe</span> ≈ <span class="hlt">Fe</span> 83.3 B 16.7 for eutectic <span class="hlt">Fe</span> 83 B 17 , [P-<span class="hlt">Fe</span> 14 ]P + [P-<span class="hlt">Fe</span> 9 ]P 2 Fe≈<span class="hlt">Fe</span> 82.8 P 17.2 for <span class="hlt">Fe</span> 83 P 17 , and [C-<span class="hlt">Fe</span> 6 ]<span class="hlt">Fe</span> 3 + [C-<span class="hlt">Fe</span> 9 ]C 2 Fe ≈ <span class="hlt">Fe</span> 82.6 C 17.4 for <span class="hlt">Fe</span> 82.7 C 17.3 . The second formulas in these dual-cluster formulas, being respectively relevant to devitrification phases <span class="hlt">Fe</span> 2 B, <span class="hlt">Fe</span> 3 P, and <span class="hlt">Fe</span> 3 C, well explain the compositions of existing <span class="hlt">Fe</span>-based transition metals-metalloid bulk metallic glasses. These formulas also satisfy the 24-electron rule. The proposition of the composition formulas for good glass formers, directly from known eutectic points, constitutes a new route towards understanding and eventual designing metallic glasses of high glass forming abilities.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28865494','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28865494"><span>Implementation and <span class="hlt">validation</span> of the extended Hill-type muscle <span class="hlt">model</span> with robust routing capabilities in LS-DYNA for active human body <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kleinbach, Christian; Martynenko, Oleksandr; Promies, Janik; Haeufle, Daniel F B; Fehr, Jörg; Schmitt, Syn</p> <p>2017-09-02</p> <p>In the state of the art finite element AHBMs for car crash analysis in the LS-DYNA software material named *MAT_MUSCLE (*MAT_156) is used for active muscles <span class="hlt">modeling</span>. It has three elements in parallel configuration, which has several major drawbacks: restraint approximation of the physical reality, complicated parameterization and absence of the integrated activation dynamics. This study presents implementation of the extended four element Hill-type muscle <span class="hlt">model</span> with serial damping and eccentric force-velocity relation including [Formula: see text] dependent activation dynamics and internal method for physiological muscle routing. Proposed <span class="hlt">model</span> was implemented into the general-purpose finite element (<span class="hlt">FE</span>) simulation software LSDYNA as a user material for truss elements. This material <span class="hlt">model</span> is verified and <span class="hlt">validated</span> with three different sets of mammalian experimental data, taken from the literature. It is compared to the *MAT_MUSCLE (*MAT_156) Hill-type muscle <span class="hlt">model</span> already existing in LS-DYNA, which is currently used in finite element human body <span class="hlt">models</span> (HBMs). An application example with an arm <span class="hlt">model</span> extracted from the <span class="hlt">FE</span> ViVA OpenHBM is given, taking into account physiological muscle paths. The simulation results show better material <span class="hlt">model</span> accuracy, calculation robustness and improved muscle routing capability compared to *MAT_156. The FORTRAN source code for the user material subroutine dyn21.f and the muscle parameters for all simulations, conducted in the study, are given at https://zenodo.org/record/826209 under an open source license. This enables a quick application of the proposed material <span class="hlt">model</span> in LS-DYNA, especially in active human body <span class="hlt">models</span> (AHBMs) for applications in automotive safety.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24422466','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24422466"><span>Redox reactions of [<span class="hlt">FeFe</span>]-hydrogenase <span class="hlt">models</span> containing an internal amine and a pendant phosphine.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zheng, Dehua; Wang, Mei; Chen, Lin; Wang, Ning; Sun, Licheng</p> <p>2014-02-03</p> <p>A diiron dithiolate complex with a pendant phosphine coordinated to one of the iron centers, [(μ-SCH2)2N(CH2C6H4-o-PPh2){<span class="hlt">Fe</span>2(CO)5}] (1), was prepared and structurally characterized. The pendant phosphine is dissociated together with a CO ligand in the presence of excess PMe3, to afford [(μ-SCH2)2N(CH2C6H4-o-PPh2){<span class="hlt">Fe</span>(CO)2(PMe3)}2] (2). Redox reactions of 2 and related complexes were studied in detail by in situ IR spectroscopy. A series of new <span class="hlt">Fe(II)Fe</span>(I) ([3](+) and [6](+)), <span class="hlt">Fe(II)Fe</span>(II) ([4](2+)), and <span class="hlt">Fe(I)Fe</span>(I) (5) complexes relevant to Hox, Hox(CO), and Hred states of the [<span class="hlt">FeFe</span>]-hydrogenase active site were detected. Among these complexes, the molecular structures of the diferrous complex [4](2+) with the internal amine and the pendant phosphine co-coordinated to the same iron center and the triphosphine diiron complex 5 were determined by X-ray crystallography. To make a comparison, the redox reactions of an analogous complex, [(μ-SCH2)2N(CH2C6H5){<span class="hlt">Fe</span>(CO)2(PMe3)}2] (7), were also investigated by in situ IR spectroscopy in the absence or presence of extrinsic PPh3, which has no influence on the oxidation reaction of 7. The pendant phosphine in the second coordination sphere makes the redox reaction of 2 different from that of its analogue 7.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21676642','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21676642"><span>Finite element <span class="hlt">modeling</span> of a 3D coupled foot-boot <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qiu, Tian-Xia; Teo, Ee-Chon; Yan, Ya-Bo; Lei, Wei</p> <p>2011-12-01</p> <p>Increasingly, musculoskeletal <span class="hlt">models</span> of the human body are used as powerful tools to study biological structures. The lower limb, and in particular the foot, is of interest because it is the primary physical interaction between the body and the environment during locomotion. The goal of this paper is to adopt the finite element (<span class="hlt">FE</span>) <span class="hlt">modeling</span> and analysis approaches to create a state-of-the-art 3D coupled foot-boot <span class="hlt">model</span> for future studies on biomechanical investigation of stress injury mechanism, foot wear design and parachute landing fall simulation. In the <span class="hlt">modeling</span> process, the foot-ankle <span class="hlt">model</span> with lower leg was developed based on Computed Tomography (CT) images using ScanIP, Surfacer and ANSYS. Then, the boot was represented by assembling the <span class="hlt">FE</span> <span class="hlt">models</span> of upper, insole, midsole and outsole built based on the <span class="hlt">FE</span> <span class="hlt">model</span> of the foot-ankle, and finally the coupled foot-boot <span class="hlt">model</span> was generated by putting together the <span class="hlt">models</span> of the lower limb and boot. In this study, the <span class="hlt">FE</span> <span class="hlt">model</span> of foot and ankle was <span class="hlt">validated</span> during balance standing. There was a good agreement in the overall patterns of predicted and measured plantar pressure distribution published in literature. The coupled foot-boot <span class="hlt">model</span> will be fully <span class="hlt">validated</span> in the subsequent works under both static and dynamic loading conditions for further studies on injuries investigation in military and sports, foot wear design and characteristics of parachute landing impact in military. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..231a2033G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..231a2033G"><span>SDG and qualitative trend based <span class="hlt">model</span> multiple scale <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Dong; Xu, Xin; Yin, Jianjin; Zhang, Hongyu; Zhang, Beike</p> <p>2017-09-01</p> <p>Verification, <span class="hlt">Validation</span> and Accreditation (VV&A) is key technology of simulation and <span class="hlt">modelling</span>. For the traditional <span class="hlt">model</span> <span class="hlt">validation</span> methods, the completeness is weak; it is carried out in one scale; it depends on human experience. The SDG (Signed Directed Graph) and qualitative trend based multiple scale <span class="hlt">validation</span> is proposed. First the SDG <span class="hlt">model</span> is built and qualitative trends are added to the <span class="hlt">model</span>. And then complete testing scenarios are produced by positive inference. The multiple scale <span class="hlt">validation</span> is carried out by comparing the testing scenarios with outputs of simulation <span class="hlt">model</span> in different scales. Finally, the effectiveness is proved by carrying out <span class="hlt">validation</span> for a reactor <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MMTA...46..190Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MMTA...46..190Z"><span><span class="hlt">Model</span> <span class="hlt">Fe</span>-Al Steel with Exceptional Resistance to High Temperature Coarsening. Part II: Experimental <span class="hlt">Validation</span> and Applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Tihe; Zhang, Peng; O'Malley, Ronald J.; Zurob, Hatem S.; Subramanian, Mani</p> <p>2015-01-01</p> <p>In order to achieve a fine uniform grain-size distribution using the process of thin slab casting and directing rolling (TSCDR), it is necessary to control the grain-size prior to the onset of thermomechanical processing. In the companion paper, <span class="hlt">Model</span> <span class="hlt">Fe</span>- Al Steel with Exceptional Resistance to High Temperature Coarsening. Part I: Coarsening Mechanism and Particle Pinning Effects, a new steel composition which uses a small volume fraction of austenite particles to pin the growth of delta-ferrite grains at high temperature was proposed and grain growth was studied in reheated samples. This paper will focus on the development of a simple laboratory-scale setup to simulate thin-slab casting of the newly developed steel and demonstrate the potential for grain size control under industrial conditions. Steel bars with different diameters are briefly dipped into the molten steel to create a shell of solidified material. These are then cooled down to room temperature at different cooling rates. During cooling, the austenite particles nucleate along the delta-ferrite grain boundaries and greatly retard grain growth. With decreasing temperature, more austenite particles precipitate, and grain growth can be completely arrested in the holding furnace. Additional applications of the <span class="hlt">model</span> alloy are discussed including grain-size control in the heat affected zone in welds and grain-growth resistance at high temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JNuM..461..282H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JNuM..461..282H"><span>Hydrogen permeation in <span class="hlt">Fe</span>CrAl alloys for LWR cladding application</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, Xunxiang; Terrani, Kurt A.; Wirth, Brian D.; Snead, Lance L.</p> <p>2015-06-01</p> <p><span class="hlt">Fe</span>CrAl, an advanced oxidation-resistant iron-based alloy class, is a highly prevalent candidate as an accident-tolerant fuel cladding material. Compared with traditional zirconium alloy fuel cladding, increased tritium permeation through <span class="hlt">Fe</span>CrAl fuel cladding to the primary coolant is expected, raising potential safety concerns. In this study, the hydrogen permeability of several <span class="hlt">Fe</span>CrAl alloys was obtained using a static permeation test station, which was calibrated and <span class="hlt">validated</span> using 304 stainless steel. The high hydrogen permeability of <span class="hlt">Fe</span>CrAl alloys leads to concerns with respect to potentially significant tritium release when used for fuel cladding in LWRs. The total tritium inventory inside the primary coolant of a light water reactor was quantified by applying a 1-dimensional steady state tritium diffusion <span class="hlt">model</span> to demonstrate the dependence of tritium inventory on fuel cladding type. Furthermore, potential mitigation strategies for tritium release from <span class="hlt">Fe</span>CrAl fuel cladding were discussed and indicate the potential for application of an alumina layer on the inner clad surface to serve as a tritium barrier. More effort is required to develop a robust, economical mitigation strategy for tritium permeation in reactors using <span class="hlt">Fe</span>CrAl clad fuel assemblies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JMMM..365...45S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JMMM..365...45S"><span>Micromagnetic finite element simulation of nanocrystalline α-<span class="hlt">Fe</span>/Nd2<span class="hlt">Fe</span>14B/<span class="hlt">Fe</span>3B magnets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saiden, N. M.; Schrefl, T.; Davies, H. A.; Hrkac, G.</p> <p>2014-09-01</p> <p>Nanocomposite Nd2<span class="hlt">Fe</span>14B permanent magnets with <span class="hlt">Fe</span>3B and α-<span class="hlt">Fe</span> as the soft phase have been simulated using micromagnetic <span class="hlt">modelling</span>. This paper reviews extensively the results from the simulation point of view. The magnetization configuration along the hysteresis loop is discussed in details. It was clear that the grain size and phase distribution play important roles in determining the magnetic properties. By changing the size of the grain and the volume fraction of the hard and soft phase, the magnetic properties change and the relationship between microstructure and properties is investigated. The remanence, Jr increases with decreasing of grain size, but oppositely for coercivity, Hc. The highest Jr, 1.46 T was obtained with a grain size 10 nm, and volume fraction of α-<span class="hlt">Fe</span>, 40%. Whereas, the highest Hc with combination Nd2<span class="hlt">Fe</span>14B 80% and 20% <span class="hlt">Fe</span>3B, 947 kA/m. On the other hand, if Nd2<span class="hlt">Fe</span>14B alone, the Hc able to reach up to 1000 kA/m. From this study, micromagnetic <span class="hlt">modelling</span> contributes to a better understanding how microstructure and phase distribution influences the magnetic properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JHyd..557..350Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JHyd..557..350Z"><span><span class="hlt">Validation</span> of 2D flood <span class="hlt">models</span> with insurance claims</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zischg, Andreas Paul; Mosimann, Markus; Bernet, Daniel Benjamin; Röthlisberger, Veronika</p> <p>2018-02-01</p> <p>Flood impact <span class="hlt">modelling</span> requires reliable <span class="hlt">models</span> for the simulation of flood processes. In recent years, flood inundation <span class="hlt">models</span> have been remarkably improved and widely used for flood hazard simulation, flood exposure and loss analyses. In this study, we <span class="hlt">validate</span> a 2D inundation <span class="hlt">model</span> for the purpose of flood exposure analysis at the river reach scale. We <span class="hlt">validate</span> the BASEMENT simulation <span class="hlt">model</span> with insurance claims using conventional <span class="hlt">validation</span> metrics. The flood <span class="hlt">model</span> is established on the basis of available topographic data in a high spatial resolution for four test cases. The <span class="hlt">validation</span> metrics were calculated with two different datasets; a dataset of event documentations reporting flooded areas and a dataset of insurance claims. The <span class="hlt">model</span> fit relating to insurance claims is in three out of four test cases slightly lower than the <span class="hlt">model</span> fit computed on the basis of the observed inundation areas. This comparison between two independent <span class="hlt">validation</span> data sets suggests that <span class="hlt">validation</span> metrics using insurance claims can be compared to conventional <span class="hlt">validation</span> data, such as the flooded area. However, a <span class="hlt">validation</span> on the basis of insurance claims might be more conservative in cases where <span class="hlt">model</span> errors are more pronounced in areas with a high density of values at risk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhRvC..80c4305O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhRvC..80c4305O"><span>Test of level density <span class="hlt">models</span> from reactions of Li6 on <span class="hlt">Fe</span>58 and Li7 on <span class="hlt">Fe</span>57</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oginni, B. M.; Grimes, S. M.; Voinov, A. V.; Adekola, A. S.; Brune, C. R.; Carter, D. E.; Heinen, Z.; Jacobs, D.; Massey, T. N.; O'Donnell, J. E.; Schiller, A.</p> <p>2009-09-01</p> <p>The reactions of Li6 on <span class="hlt">Fe</span>58 and Li7 on <span class="hlt">Fe</span>57 have been studied at 15 MeV beam energy. These two reactions produce the same compound nucleus, Cu64. The charged particle spectra were measured at backward angles. The data obtained have been compared with Hauser-Feshbach <span class="hlt">model</span> calculations. The level density parameters of Ni63 and Co60 have been obtained from the particle evaporation spectra. We also find contributions from the break up of the lithium projectiles to the low energy region of the α spectra.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140013190','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140013190"><span>Astronaut Bone Medical Standards Derived from Finite Element (<span class="hlt">FE</span>) <span class="hlt">Models</span> of QCT Scans from Population Studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sibonga, J. D.; Feiveson, A. H.</p> <p>2014-01-01</p> <p>This work was accomplished in support of the Finite Element [<span class="hlt">FE</span>] Strength Task Group, NASA Johnson Space Center [JSC], Houston, TX. This group was charged with the task of developing rules for using finite-element [<span class="hlt">FE</span>] bone-strength measures to construct operating bands for bone health that are relevant to astronauts following exposure to spaceflight. <span class="hlt">FE</span> <span class="hlt">modeling</span> is a computational tool used by engineers to estimate the failure loads of complex structures. Recently, some engineers have used this tool to characterize the failure loads of the hip in population studies that also monitored fracture outcomes. A Directed Research Task was authorized in July, 2012 to investigate <span class="hlt">FE</span> data from these population studies to derive these proposed standards of bone health as a function of age and gender. The proposed standards make use of an <span class="hlt">FE</span>-based index that integrates multiple contributors to bone strength, an expanded evaluation that is critical after an astronaut is exposed to spaceflight. The current index of bone health used by NASA is the measurement of areal BMD. There was a concern voiced by a research and clinical advisory panel that the sole use of areal BMD would be insufficient to fully evaluate the effects of spaceflight on the hip. Hence, NASA may not have a full understanding of fracture risk, both during and after a mission, and may be poorly estimating in-flight countermeasure efficacy. The <span class="hlt">FE</span> Strength Task Group - composed of principal investigators of the aforementioned population studies and of <span class="hlt">FE</span> <span class="hlt">modelers</span> -donated some of its population QCT data to estimate of hip bone strength by <span class="hlt">FE</span> <span class="hlt">modeling</span> for this specific purpose. Consequently, Human Health Countermeasures [HHC] has compiled a dataset of <span class="hlt">FE</span> hip strengths, generated by a single <span class="hlt">FE</span> <span class="hlt">modeling</span> approach, from human subjects (approx.1060) with ages covering the age range of the astronauts. The dataset has been analyzed to generate a set of <span class="hlt">FE</span> strength cutoffs for the following scenarios: a) Qualify an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29113934','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29113934"><span><span class="hlt">Validating</span> EHR clinical <span class="hlt">models</span> using ontology patterns.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Martínez-Costa, Catalina; Schulz, Stefan</p> <p>2017-12-01</p> <p>Clinical <span class="hlt">models</span> are artefacts that specify how information is structured in electronic health records (EHRs). However, the makeup of clinical <span class="hlt">models</span> is not guided by any formal constraint beyond a semantically vague information <span class="hlt">model</span>. We address this gap by advocating ontology design patterns as a mechanism that makes the semantics of clinical <span class="hlt">models</span> explicit. This paper demonstrates how ontology design patterns can <span class="hlt">validate</span> existing clinical <span class="hlt">models</span> using SHACL. Based on the Clinical Information <span class="hlt">Modelling</span> Initiative (CIMI), we show how ontology patterns detect both <span class="hlt">modeling</span> and terminology binding errors in CIMI <span class="hlt">models</span>. SHACL, a W3C constraint language for the <span class="hlt">validation</span> of RDF graphs, builds on the concept of "Shape", a description of data in terms of expected cardinalities, datatypes and other restrictions. SHACL, as opposed to OWL, subscribes to the Closed World Assumption (CWA) and is therefore more suitable for the <span class="hlt">validation</span> of clinical <span class="hlt">models</span>. We have demonstrated the feasibility of the approach by manually describing the correspondences between six CIMI clinical <span class="hlt">models</span> represented in RDF and two SHACL ontology design patterns. Using a Java-based SHACL implementation, we found at least eleven <span class="hlt">modeling</span> and binding errors within these CIMI <span class="hlt">models</span>. This demonstrates the usefulness of ontology design patterns not only as a <span class="hlt">modeling</span> tool but also as a tool for <span class="hlt">validation</span>. Copyright © 2017 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870064649&hterms=donation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddonation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870064649&hterms=donation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddonation"><span>The bonding of <span class="hlt">Fe</span>N2, <span class="hlt">Fe</span>CO, and <span class="hlt">Fe</span>2N2 - <span class="hlt">Model</span> systems for side-on bonding of CO and N2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bauschlicher, Charles W., Jr.; Pettersson, Lars G. M.; Siegbahn, Per E. M.</p> <p>1987-01-01</p> <p>Qualitative calculations are performed to elucidate the nature of the side-on interaction of both N2 and CO with a single <span class="hlt">Fe</span> atom. The systems are found to be quite similar, with bonding leading to an increase in the CO or N2 bond length and a decrease in the vibrational frequency. The CO or N2 stretching modes lead to a large dipole derivative along the metal-ligand bond axis. The populations show an almost identical, large donation from the <span class="hlt">Fe</span> 3d orbitals into the CO or N2 Pi-asterisk. The larger system <span class="hlt">Fe</span>2N2 is then considered, with the N2 bridging the <span class="hlt">Fe</span>2, both parallel and perpendicular to the <span class="hlt">Fe</span>2 bond axis for two different <span class="hlt">Fe-Fe</span> distances. For <span class="hlt">Fe</span>N2, the shift in the observed N2 frequency is smaller than observed for the alpha state of N2/<span class="hlt">Fe</span>(111). The shift in the N2 vibrational frequency increases when the N2 interacts with two <span class="hlt">Fe</span> atoms, either at the <span class="hlt">Fe-Fe</span> nearest neighbor distance or at the first layer <span class="hlt">Fe-Fe</span> distance, when the side-on N2 axis is oriented perpendicular to an <span class="hlt">Fe-Fe</span> bond.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994JAP....75.6187H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994JAP....75.6187H"><span>``Loose spins'' in <span class="hlt">Fe/Cu/Fe</span>(001) structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heinrich, B.; Celinski, Z.; Liao, L. X.; From, M.; Cochran, J. F.</p> <p>1994-05-01</p> <p>Slonczewski recently proposed a <span class="hlt">model</span> for the exchange coupling between ferromagnetic layers separated by a nonferromagnetic spacer based on the concept of ``loose spins.'' ``Loose spins'' contribute to the total exchange energy. We have studied the role of ``loose spins'' in bcc <span class="hlt">Fe/Cu/Fe</span>(001) structures. bcc <span class="hlt">Fe/Cu/Fe</span>(001) trilayers deposited at room temperature were investigated extensively in our previous studies. In our ``loose spin'' studies, the <span class="hlt">Fe</span> was added inside the Cu interlayer. Several structures were atomically engineered in order to test the behavior of ``loose spins:'' One additional atomic layer of an (<span class="hlt">Fe</span>+Cu) alloy were located in appropriate positions in a Cu spacer. The bilinear and biquadratic exchange coupling in the above structures was quantitatively studied with FMR in the temperature range 77-370 K and with MOKE at RT.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/3604','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/3604"><span><span class="hlt">Validation</span> of urban freeway <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>2015-01-01</p> <p>This report describes the methodology, data, conclusions, and enhanced <span class="hlt">models</span> regarding the <span class="hlt">validation</span> of two sets of <span class="hlt">models</span> developed in the Strategic Highway Research Program 2 (SHRP 2) Reliability Project L03, Analytical Procedures for Determining...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140003976','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140003976"><span>Turbulence <span class="hlt">Modeling</span> Verification and <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rumsey, Christopher L.</p> <p>2014-01-01</p> <p>Computational fluid dynamics (CFD) software that solves the Reynolds-averaged Navier-Stokes (RANS) equations has been in routine use for more than a quarter of a century. It is currently employed not only for basic research in fluid dynamics, but also for the analysis and design processes in many industries worldwide, including aerospace, automotive, power generation, chemical manufacturing, polymer processing, and petroleum exploration. A key feature of RANS CFD is the turbulence <span class="hlt">model</span>. Because the RANS equations are unclosed, a <span class="hlt">model</span> is necessary to describe the effects of the turbulence on the mean flow, through the Reynolds stress terms. The turbulence <span class="hlt">model</span> is one of the largest sources of uncertainty in RANS CFD, and most <span class="hlt">models</span> are known to be flawed in one way or another. Alternative methods such as direct numerical simulations (DNS) and large eddy simulations (LES) rely less on <span class="hlt">modeling</span> and hence include more physics than RANS. In DNS all turbulent scales are resolved, and in LES the large scales are resolved and the effects of the smallest turbulence scales are <span class="hlt">modeled</span>. However, both DNS and LES are too expensive for most routine industrial usage on today's computers. Hybrid RANS-LES, which blends RANS near walls with LES away from walls, helps to moderate the cost while still retaining some of the scale-resolving capability of LES, but for some applications it can still be too expensive. Even considering its associated uncertainties, RANS turbulence <span class="hlt">modeling</span> has proved to be very useful for a wide variety of applications. For example, in the aerospace field, many RANS <span class="hlt">models</span> are considered to be reliable for computing attached flows. However, existing turbulence <span class="hlt">models</span> are known to be inaccurate for many flows involving separation. Research has been ongoing for decades in an attempt to improve turbulence <span class="hlt">models</span> for separated and other nonequilibrium flows. When developing or improving turbulence <span class="hlt">models</span>, both verification and <span class="hlt">validation</span> are important</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27562611','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27562611"><span>Binder-jetting 3D printing and alloy development of new biodegradable <span class="hlt">Fe</span>-Mn-Ca/Mg alloys.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hong, Daeho; Chou, Da-Tren; Velikokhatnyi, Oleg I; Roy, Abhijit; Lee, Boeun; Swink, Isaac; Issaev, Ilona; Kuhn, Howard A; Kumta, Prashant N</p> <p>2016-11-01</p> <p>3D printing of various biomaterials including titanium and stainless steel has been studied for treating patients with cranio-maxillofacial bone defect. The potential long term complications with use of inert biometals have opened the opportunities for use of biodegradable metals in the clinical arena. The authors previously reported that binder-jet 3D printing technique enhanced the degradation rates of biodegradable <span class="hlt">Fe</span>-Mn alloy by creating engineered micropores rendering the system attractive as biodegradable implantable devices. In the present study, the authors employed CALPHAD <span class="hlt">modeling</span> to systematically study and modify the <span class="hlt">Fe</span>-Mn alloy composition to achieve enhanced degradation rates. Accordingly, Ca and Mg addition to <span class="hlt">Fe</span>-35wt% Mn solid solution predicted increase in degradation rates. In order to <span class="hlt">validate</span> the CALPHAD results, <span class="hlt">Fe</span> - (35-y)wt% Mn - ywt% X (X=Ca, Mg, and y=0, 1, 2) were synthesized by using high energy mechanical alloying (HEMA). Sintered pellets of <span class="hlt">Fe</span>-Mn-Ca and <span class="hlt">Fe</span>-Mn-Mg were then subjected to potentiodynamic polarization (PDP) and live/dead cell viability tests. Sintered pellets of <span class="hlt">Fe</span>-Mn, <span class="hlt">Fe</span>-Mn-Ca, and <span class="hlt">Fe</span>-Mn-Mg also exhibited MC3T3 murine pre-osteoblast cells viability in the live/dead assay results. <span class="hlt">Fe</span>-Mn and <span class="hlt">Fe</span>-Mn-1Ca were thus accordingly selected for 3D printing and the results further confirmed enhanced degradation of Ca addition to 3D printed constructs <span class="hlt">validating</span> the theoretical and alloy development studies. Live/dead and MTT cell viability results also confirmed good cytocompatibility of the 3D-printed <span class="hlt">Fe</span>-Mn and <span class="hlt">Fe</span>-Mn-1Ca constructs. Bone grafting is widely used for the treatment of cranio-maxillofacial bone injuries. 3D printing of biodegradable <span class="hlt">Fe</span> alloy is anticipated to be advantageous over current bone grafting techniques. 3D printing offers the fabrication of precise and tailored bone grafts to fit the patient specific bone defect needs. Biodegradable <span class="hlt">Fe</span> alloy is a good candidate for 3D printing synthetic grafts to regenerate bone</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.739a2016M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.739a2016M"><span>Melting Penetration Simulation of <span class="hlt">Fe</span>-U System at High Temperature Using MPS_LER</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mustari, A. P. A.; Yamaji, A.; Irwanto, Dwi</p> <p>2016-08-01</p> <p>Melting penetration information of <span class="hlt">Fe</span>-U system is necessary for simulating the molten core behavior during severe accident in nuclear power plants. For <span class="hlt">Fe</span>-U system, the information is mainly obtained from experiment, i.e. TREAT experiment. However, there is no reported data on SS304 at temperature above 1350°C. The MPS_LER has been developed and <span class="hlt">validated</span> to simulate melting penetration on <span class="hlt">Fe</span>-U system. The MPS_LER <span class="hlt">modelled</span> the eutectic phenomenon by solving the diffusion process and by applying the binary phase diagram criteria. This study simulates the melting penetration of the system at higher temperature using MPS_LER. Simulations were conducted on SS304 at 1400, 1450 and 1500°C. The simulation results show rapid increase of melting penetration rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012Metro..49..785B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012Metro..49..785B"><span>A new 3D finite element <span class="hlt">model</span> of the IEC 60318-1 artificial ear: II. Experimental and numerical <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bravo, Agustín; Barham, Richard; Ruiz, Mariano; López, Juan Manuel; De Arcas, Guillermo; Alonso, Jesus</p> <p>2012-12-01</p> <p>In part I, the feasibility of using three-dimensional (3D) finite elements (FEs) to <span class="hlt">model</span> the acoustic behaviour of the IEC 60318-1 artificial ear was studied and the numerical approach compared with classical lumped elements <span class="hlt">modelling</span>. It was shown that by using a more complex acoustic <span class="hlt">model</span> that took account of thermo-viscous effects, geometric shapes and dimensions, it was possible to develop a realistic <span class="hlt">model</span>. This <span class="hlt">model</span> then had clear advantages in comparison with the <span class="hlt">models</span> based on equivalent circuits using lumped parameters. In fact results from <span class="hlt">FE</span> <span class="hlt">modelling</span> produce a better understanding about the physical phenomena produced inside ear simulator couplers, facilitating spatial and temporal visualization of the sound fields produced. The objective of this study (part II) is to extend the investigation by <span class="hlt">validating</span> the numerical calculations against measurements on an ear simulator conforming to IEC 60318-1. For this purpose, an appropriate commercially available device is taken and a complete 3D <span class="hlt">FE</span> <span class="hlt">model</span> developed for it. The numerical <span class="hlt">model</span> is based on key dimensional data obtained with a non-destructive x-ray inspection technique. Measurements of the acoustic transfer impedance have been carried out on the same device at a national measurement institute using the method embodied in IEC 60318-1. Having accounted for the actual device dimensions, the thermo-viscous effects inside narrow slots and holes and environmental conditions, the results of the numerical <span class="hlt">modelling</span> were found to be in good agreement with the measured values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhRvB..80j4440N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhRvB..80j4440N"><span><span class="hlt">Model</span> many-body Stoner Hamiltonian for binary <span class="hlt">Fe</span>Cr alloys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nguyen-Manh, D.; Dudarev, S. L.</p> <p>2009-09-01</p> <p>We derive a <span class="hlt">model</span> tight-binding many-body d -electron Stoner Hamiltonian for <span class="hlt">Fe</span>Cr binary alloys and investigate the sensitivity of its mean-field solutions to the choice of hopping integrals and the Stoner exchange parameters. By applying the local charge-neutrality condition within a self-consistent treatment we show that the negative enthalpy-of-mixing anomaly characterizing the alloy in the low chromium concentration limit is due entirely to the presence of the on-site exchange Stoner terms and that the occurrence of this anomaly is not specifically related to the choice of hopping integrals describing conventional chemical bonding between atoms in the alloy. The Bain transformation pathway computed, using the proposed <span class="hlt">model</span> Hamiltonian, for the <span class="hlt">Fe</span>15Cr alloy configuration is in excellent agreement with ab initio total-energy calculations. Our investigation also shows how the parameters of a tight-binding many-body <span class="hlt">model</span> Hamiltonian for a magnetic alloy can be derived from the comparison of its mean-field solutions with other, more accurate, mean-field approximations (e.g., density-functional calculations), hence stimulating the development of large-scale computational algorithms for <span class="hlt">modeling</span> radiation damage effects in magnetic alloys and steels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1376905','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1376905"><span>Nuclear Energy Advanced <span class="hlt">Modeling</span> and Simulation (NEAMS) Accident Tolerant Fuels High Impact Problem: Coordinate Multiscale <span class="hlt">Fe</span>CrAl <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gamble, K. A.; Hales, J. D.; Zhang, Y.</p> <p></p> <p>Since the events at the Fukushima-Daiichi nuclear power plant in March 2011 significant research has unfolded at national laboratories, universities and other institutions into alternative materials that have potential enhanced ac- cident tolerance when compared to traditional UO2 fuel zircaloy clad fuel rods. One of the potential replacement claddings are iron-chromium-alunimum (<span class="hlt">Fe</span>CrAl) alloys due to their increased oxidation resistance [1–4] and higher strength [1, 2]. While the oxidation characteristics of <span class="hlt">Fe</span>CrAl are a benefit for accident tolerance, the thermal neu- tron absorption cross section of <span class="hlt">Fe</span>CrAl is about ten times that of Zircaloy. This neutronic penalty necessitates thinner cladding. Thismore » allows for slightly larger pellets to give the same cold gap width in the rod. However, the slight increase in pellet diameter is not sufficient to compensate for the neutronic penalty and enriching the fuel beyond the current 5% limit appears to be necessary [5]. Current estimates indicate that this neutronic penalty will impose an increase in fuel cost of 15-35% [1, 2]. In addition to the neutronic disadvantage, it is anticipated that tritium release to the coolant will be larger because the permeability of hydrogen in <span class="hlt">Fe</span>CrAl is about 100 times higher than in Zircaloy [6]. Also, radiation-induced hardening and embrittlement of <span class="hlt">Fe</span>CrAl need to be fully characterized experimentally [7]. Due to the aggressive development schedule for inserting some of the potential materials into lead test assemblies or rods by 2022 [8] multiscale multiphysics <span class="hlt">modeling</span> approaches have been used to provide insight into these the use of <span class="hlt">Fe</span>CrAl as a cladding material. The purpose of this letter report is to highlight the multiscale <span class="hlt">modeling</span> effort for iron-chromium-alunimum (<span class="hlt">Fe</span>CrAl) cladding alloys as part of the Nuclear Energy Advanced <span class="hlt">Modeling</span> and Simulation (NEAMS) program through its Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The approach taken throughout the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23625564','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23625564"><span>Research of the relationship of pedestrian injury to collision speed, car-type, impact location and pedestrian sizes using human <span class="hlt">FE</span> <span class="hlt">model</span> (THUMS Version 4).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Watanabe, Ryosuke; Katsuhara, Tadasuke; Miyazaki, Hiroshi; Kitagawa, Yuichi; Yasuki, Tsuyoshi</p> <p>2012-10-01</p> <p>Injuries in car to pedestrian collisions are affected by various factors such as the vehicle body type, pedestrian body size and impact location as well as the collision speed. This study aimed to investigate the influence of such factors taking a Finite Element (<span class="hlt">FE</span>) approach. A total of 72 collision cases were simulated using three different vehicle <span class="hlt">FE</span> <span class="hlt">models</span> (Sedan, SUV, Mini-Van), three different pedestrian <span class="hlt">FE</span> <span class="hlt">models</span> (AM50, AF05, AM95), assuming two different impact locations (center and the corner of the bumper) and at four different collision speeds (20, 30, 40 and 50 km/h). The impact kinematics and the responses of the pedestrian <span class="hlt">model</span> were <span class="hlt">validated</span> against those in the literature prior to the simulations. The relationship between the collision speed and the predicted occurrence of head and chest injuries was examined for each case, analyzing the impact kinematics of the pedestrian against the vehicle body and resultant loading to the head and the chest. Strain based indicators were used in the simulation <span class="hlt">model</span> to estimate skeletal injury (bony fracture) and soft tissue (brain and internal organs) injury. The study results primarily showed that the injury risk became higher with the collision speed, but was also affected by the combination of the factors such as the pedestrian size and the impact location. The study also discussed the injury patterns and trends with respect to the factors examined. In all of the simulated conditions, the <span class="hlt">model</span> did not predict any severe injury at a collision speed of 20 km/h.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA553644','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA553644"><span>Cultural Geography <span class="hlt">Model</span> <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2010-03-01</p> <p>the Cultural Geography <span class="hlt">Model</span> (CGM), a government owned, open source multi - agent system utilizing Bayesian networks, queuing systems, the Theory of...referent determined either from theory or SME opinion. 4. CGM Overview The CGM is a government-owned, open source, data driven multi - agent social...HSCB, <span class="hlt">validation</span>, social network analysis ABSTRACT: In the current warfighting environment , the military needs robust <span class="hlt">modeling</span> and simulation (M&S</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1185774-hydrogen-permeation-fecral-alloys-lwr-cladding-application','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1185774-hydrogen-permeation-fecral-alloys-lwr-cladding-application"><span>Hydrogen permeation in <span class="hlt">Fe</span>CrAl alloys for LWR cladding application</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Hu, Xunxiang; Terrani, Kurt A.; Wirth, Brian D.; ...</p> <p>2015-03-19</p> <p><span class="hlt">Fe</span>CrAl is an advanced oxidation-resistant iron-based alloy class, is a highly prevalent candidate as an accident-tolerant fuel cladding material. Compared with traditional zirconium alloy fuel cladding, increased tritium permeation through <span class="hlt">Fe</span>CrAl fuel cladding to the primary coolant is expected, raising potential safety concerns. In our study, the hydrogen permeability of several <span class="hlt">Fe</span>CrAl alloys was obtained using a static permeation test station, which was calibrated and <span class="hlt">validated</span> using 304 stainless steel. The high hydrogen permeability of <span class="hlt">Fe</span>CrAl alloys leads to concerns with respect to potentially significant tritium release when used for fuel cladding in LWRs. Also, the total tritium inventory insidemore » the primary coolant of a light water reactor was quantified by applying a 1-dimensional steady state tritium diffusion <span class="hlt">model</span> to demonstrate the dependence of tritium inventory on fuel cladding type. Furthermore, potential mitigation strategies for tritium release from <span class="hlt">Fe</span>CrAl fuel cladding were discussed and indicate the potential for application of an alumina layer on the inner clad surface to serve as a tritium barrier. More effort is required to develop a robust, economical mitigation strategy for tritium permeation in reactors using <span class="hlt">Fe</span>CrAl clad fuel assemblies.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018RJPCA..92..829A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018RJPCA..92..829A"><span>Analysis of the Glass-Forming Ability of <span class="hlt">Fe</span>-Er Alloys, Based on Thermodynamic <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arutyunyan, N. A.; Zaitsev, A. I.; Dunaev, S. F.; Kalmykov, K. B.; El'nyakov, D. D.; Shaposhnikov, N. G.</p> <p>2018-05-01</p> <p>The <span class="hlt">Fe</span>-Er phase diagram and thermodynamic properties of all its phases are assessed by means of self-consistent analysis. To refine the data on phase equilibria in the <span class="hlt">Fe</span>-Er system, an investigation is performed in the 10-40 at % range of Er concentrations. The temperature-concentration dependences of the thermodynamic properties of a melt are presented using the <span class="hlt">model</span> of ideal associated solutions. Thermodynamic parameters of each phase are obtained, and the calculated results are in agreement with available experimental data. The correlation between the thermodynamic properties of liquid <span class="hlt">Fe</span>-Er alloys and their tendency toward amorphization are studied. It is shown that compositions of amorphous alloys prepared by melt quenching coincide with the ranges of concentration with the predominance of <span class="hlt">Fe</span>3Er and <span class="hlt">Fe</span>Er2 associative groups that have large negative entropies of formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24831111','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24831111"><span>A combined experimental and finite element analysis method for the estimation of eddy-current loss in Nd<span class="hlt">Fe</span>B magnets.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fratila, Radu; Benabou, Abdelkader; Tounzi, Abdelmounaïm; Mipo, Jean-Claude</p> <p>2014-05-14</p> <p>Nd<span class="hlt">Fe</span>B permanent magnets (PMs) are widely used in high performance electrical machines, but their relatively high conductivity subjects them to eddy current losses that can lead to magnetization loss. The Finite Element (<span class="hlt">FE</span>) method is generally used to quantify the eddy current loss of PMs, but it remains quite difficult to <span class="hlt">validate</span> the accuracy of the results with complex devices. In this paper, an experimental test device is used in order to extract the eddy current losses that are then compared with those of a 3D <span class="hlt">FE</span> <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApSS..273..173S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApSS..273..173S"><span><span class="hlt">Validity</span> of "sputtering and re-condensation" <span class="hlt">model</span> in active screen cage plasma nitriding process</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saeed, A.; Khan, A. W.; Jan, F.; Abrar, M.; Khalid, M.; Zakaullah, M.</p> <p>2013-05-01</p> <p>The <span class="hlt">validity</span> of "sputtering and re-condensation" <span class="hlt">model</span> in active screen plasma nitriding for nitrogen mass transfer mechanism is investigated. The dominant species including NH, <span class="hlt">Fe</span>-I, N2+, N-I and N2 along with Hα and Hβ lines are observed in the optical emission spectroscopy (OES) analysis. Active screen cage and dc plasma nitriding of AISI 316 stainless steel as function of treatment time is also investigated. The structure and phases composition of the nitrided layer is studied by X-ray diffraction (XRD). Surface morphology is studied by scanning electron microscopy (SEM) and hardness profile is obtained by Vicker's microhardness tester. Increasing trend in microhardness is observed in both cases but the increase in active screen plasma nitriding is about 3 times greater than that achieved by dc plasma nitriding. On the basis of metallurgical and OES observations the use of "sputtering and re-condensation" <span class="hlt">model</span> in active screen plasma nitriding is tested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28888181','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28888181"><span>External <span class="hlt">validation</span> of preexisting first trimester preeclampsia prediction <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Allen, Rebecca E; Zamora, Javier; Arroyo-Manzano, David; Velauthar, Luxmilar; Allotey, John; Thangaratinam, Shakila; Aquilina, Joseph</p> <p>2017-10-01</p> <p>To <span class="hlt">validate</span> the increasing number of prognostic <span class="hlt">models</span> being developed for preeclampsia using our own prospective study. A systematic review of literature that assessed biomarkers, uterine artery Doppler and maternal characteristics in the first trimester for the prediction of preeclampsia was performed and <span class="hlt">models</span> selected based on predefined criteria. <span class="hlt">Validation</span> was performed by applying the regression coefficients that were published in the different derivation studies to our cohort. We assessed the <span class="hlt">models</span> discrimination ability and calibration. Twenty <span class="hlt">models</span> were identified for <span class="hlt">validation</span>. The discrimination ability observed in derivation studies (Area Under the Curves) ranged from 0.70 to 0.96 when these <span class="hlt">models</span> were <span class="hlt">validated</span> against the <span class="hlt">validation</span> cohort, these AUC varied importantly, ranging from 0.504 to 0.833. Comparing Area Under the Curves obtained in the derivation study to those in the <span class="hlt">validation</span> cohort we found statistically significant differences in several studies. There currently isn't a definitive prediction <span class="hlt">model</span> with adequate ability to discriminate for preeclampsia, which performs as well when applied to a different population and can differentiate well between the highest and lowest risk groups within the tested population. The pre-existing large number of <span class="hlt">models</span> limits the value of further <span class="hlt">model</span> development and future research should be focussed on further attempts to <span class="hlt">validate</span> existing <span class="hlt">models</span> and assessing whether implementation of these improves patient care. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511059F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511059F"><span>Calibration and <span class="hlt">validation</span> of rockfall <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frattini, Paolo; Valagussa, Andrea; Zenoni, Stefania; Crosta, Giovanni B.</p> <p>2013-04-01</p> <p>Calibrating and <span class="hlt">validating</span> landslide <span class="hlt">models</span> is extremely difficult due to the particular characteristic of landslides: limited recurrence in time, relatively low frequency of the events, short durability of post-event traces, poor availability of continuous monitoring data, especially for small landslide and rockfalls. For this reason, most of the rockfall <span class="hlt">models</span> presented in literature completely lack calibration and <span class="hlt">validation</span> of the results. In this contribution, we explore different strategies for rockfall <span class="hlt">model</span> calibration and <span class="hlt">validation</span> starting from both an historical event and a full-scale field test. The event occurred in 2012 in Courmayeur (Western Alps, Italy), and caused serious damages to quarrying facilities. This event has been studied soon after the occurrence through a field campaign aimed at mapping the blocks arrested along the slope, the shape and location of the detachment area, and the traces of scars associated to impacts of blocks on the slope. The full-scale field test was performed by Geovert Ltd in the Christchurch area (New Zealand) after the 2011 earthquake. During the test, a number of large blocks have been mobilized from the upper part of the slope and filmed with high velocity cameras from different viewpoints. The movies of each released block were analysed to identify the block shape, the propagation path, the location of impacts, the height of the trajectory and the velocity of the block along the path. Both calibration and <span class="hlt">validation</span> of rockfall <span class="hlt">models</span> should be based on the optimization of the agreement between the actual trajectories or location of arrested blocks and the simulated ones. A measure that describe this agreement is therefore needed. For calibration purpose, this measure should simple enough to allow trial and error repetitions of the <span class="hlt">model</span> for parameter optimization. In this contribution we explore different calibration/<span class="hlt">validation</span> measures: (1) the percentage of simulated blocks arresting within a buffer of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3432505','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3432505"><span>Connecting [Ni<span class="hlt">Fe</span>]- and [<span class="hlt">FeFe</span>]-Hydrogenases: Mixed-Valence Nickel-Iron Dithiolates With Rotated Structures</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Schilter, David; Rauchfuss, Thomas B.; Stein, Matthias</p> <p>2012-01-01</p> <p>A series of mixed-valence iron-nickel dithiolates is described that exhibits structures similar to those of mixed-valence diiron dithiolates. Interaction of tricarbonyl salt [(dppe)Ni(pdt)<span class="hlt">Fe</span>(CO)3]BF4 ([1]BF4, dppe = Ph2PCH2CH2PPh2, pdtH2 = HSCH2CH2CH2SH) with P-donor ligands (L) afforded the substituted derivatives [(dppe)Ni(pdt)<span class="hlt">Fe</span>(CO)2L]BF4 incorporating L = PHCy2 ([1a]BF4), PPh(NEt2)2 ([1b]BF4), P(NMe2)3 ([1c]BF4), P(i-Pr)3 ([1d]BF4) and PCy3 ([1e]BF4). The related precursor [(dcpe)Ni(pdt)<span class="hlt">Fe</span>(CO)3]BF4 ([2]BF4, dcpe = Cy2PCH2CH2PCy2) gave the more electron-rich family of compounds [(dcpe)Ni(pdt)<span class="hlt">Fe</span>(CO)2L]BF4 for L = PPh2(2-pyridyl) ([2a]BF4), PPh3 ([2b]BF4) and PCy3 ([2c]BF4). For bulky and strongly basic monophosphorus ligands, the salts feature distorted <span class="hlt">Fe</span> coordination geometries: crystallographic analyses of [1e]BF4 and [2c]BF4 showed they adopt ‘rotated’ <span class="hlt">Fe</span>(I) centers, in which PCy3 occupies a basal site and one CO ligand partially bridges the Ni and <span class="hlt">Fe</span> centers. Like the undistorted mixed-valence derivatives, the new class of complexes are described as Ni(II)<span class="hlt">Fe</span>(I) (S = ½) systems according to EPR spectroscopy, although with attenuated 31P hyperfine interactions. DFT calculations using the BP86, B3LYP, and PBE0 exchange-correlation functionals agree with the structural and spectroscopic data, suggesting that the spin for [1e]+ is localized in a <span class="hlt">Fe</span>(I)-centered d(z2) orbital, orthogonal to the <span class="hlt">Fe</span>-P bond. The PCy3 complexes, rare examples of species featuring ‘rotated’ <span class="hlt">Fe</span> centers, both structurally and spectroscopically resemble mixed-valence diiron dithiolates. Also reproducing the NiS2<span class="hlt">Fe</span> core of the [Ni<span class="hlt">Fe</span>]-H2ase active site, the hybrid <span class="hlt">models</span> incorporate key features of the two major classes of H2ase. Furthermore, cyclic voltammetry experiments suggest that the highly basic phosphine ligands enable a second oxidation corresponding to the couple [(dxpe)Ni(pdt)<span class="hlt">Fe</span>(CO)2L]+/2+. The resulting unsaturated 32e− dications represent the closest approach to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MSSP...84..194E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MSSP...84..194E"><span>Nonlinear finite element <span class="hlt">model</span> updating for damage identification of civil structures using batch Bayesian estimation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ebrahimian, Hamed; Astroza, Rodrigo; Conte, Joel P.; de Callafon, Raymond A.</p> <p>2017-02-01</p> <p>This paper presents a framework for structural health monitoring (SHM) and damage identification of civil structures. This framework integrates advanced mechanics-based nonlinear finite element (<span class="hlt">FE</span>) <span class="hlt">modeling</span> and analysis techniques with a batch Bayesian estimation approach to estimate time-invariant <span class="hlt">model</span> parameters used in the <span class="hlt">FE</span> <span class="hlt">model</span> of the structure of interest. The framework uses input excitation and dynamic response of the structure and updates a nonlinear <span class="hlt">FE</span> <span class="hlt">model</span> of the structure to minimize the discrepancies between predicted and measured response time histories. The updated <span class="hlt">FE</span> <span class="hlt">model</span> can then be interrogated to detect, localize, classify, and quantify the state of damage and predict the remaining useful life of the structure. As opposed to recursive estimation methods, in the batch Bayesian estimation approach, the entire time history of the input excitation and output response of the structure are used as a batch of data to estimate the <span class="hlt">FE</span> <span class="hlt">model</span> parameters through a number of iterations. In the case of non-informative prior, the batch Bayesian method leads to an extended maximum likelihood (ML) estimation method to estimate jointly time-invariant <span class="hlt">model</span> parameters and the measurement noise amplitude. The extended ML estimation problem is solved efficiently using a gradient-based interior-point optimization algorithm. Gradient-based optimization algorithms require the <span class="hlt">FE</span> response sensitivities with respect to the <span class="hlt">model</span> parameters to be identified. The <span class="hlt">FE</span> response sensitivities are computed accurately and efficiently using the direct differentiation method (DDM). The estimation uncertainties are evaluated based on the Cramer-Rao lower bound (CRLB) theorem by computing the exact Fisher Information matrix using the <span class="hlt">FE</span> response sensitivities with respect to the <span class="hlt">model</span> parameters. The accuracy of the proposed uncertainty quantification approach is verified using a sampling approach based on the unscented transformation. Two <span class="hlt">validation</span> studies, based on realistic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3667097','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3667097"><span>External <span class="hlt">validation</span> of a Cox prognostic <span class="hlt">model</span>: principles and methods</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2013-01-01</p> <p>Background A prognostic <span class="hlt">model</span> should not enter clinical practice unless it has been demonstrated that it performs a useful role. External <span class="hlt">validation</span> denotes evaluation of <span class="hlt">model</span> performance in a sample independent of that used to develop the <span class="hlt">model</span>. Unlike for logistic regression <span class="hlt">models</span>, external <span class="hlt">validation</span> of Cox <span class="hlt">models</span> is sparsely treated in the literature. Successful <span class="hlt">validation</span> of a <span class="hlt">model</span> means achieving satisfactory discrimination and calibration (prediction accuracy) in the <span class="hlt">validation</span> sample. <span class="hlt">Validating</span> Cox <span class="hlt">models</span> is not straightforward because event probabilities are estimated relative to an unspecified baseline function. Methods We describe statistical approaches to external <span class="hlt">validation</span> of a published Cox <span class="hlt">model</span> according to the level of published information, specifically (1) the prognostic index only, (2) the prognostic index together with Kaplan-Meier curves for risk groups, and (3) the first two plus the baseline survival curve (the estimated survival function at the mean prognostic index across the sample). The most challenging task, requiring level 3 information, is assessing calibration, for which we suggest a method of approximating the baseline survival function. Results We apply the methods to two comparable datasets in primary breast cancer, treating one as derivation and the other as <span class="hlt">validation</span> sample. Results are presented for discrimination and calibration. We demonstrate plots of survival probabilities that can assist <span class="hlt">model</span> evaluation. Conclusions Our <span class="hlt">validation</span> methods are applicable to a wide range of prognostic studies and provide researchers with a toolkit for external <span class="hlt">validation</span> of a published Cox <span class="hlt">model</span>. PMID:23496923</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H51C1214S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H51C1214S"><span>Reactive Transport <span class="hlt">Modeling</span> of Microbe-mediated <span class="hlt">Fe</span> (II) Oxidation for Enhanced Oil Recovery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Surasani, V.; Li, L.</p> <p>2011-12-01</p> <p>Microbially Enhanced Oil Recovery (MEOR) aims to improve the recovery of entrapped heavy oil in depleted reservoirs using microbe-based technology. Reservoir ecosystems often contain diverse microbial communities those can interact with subsurface fluids and minerals through a network of nutrients and energy fluxes. Microbe-mediated reactions products include gases, biosurfactants, biopolymers those can alter the properties of oil and interfacial interactions between oil, brine, and rocks. In addition, the produced biomass and mineral precipitates can change the reservoir permeability profile and increase sweeping efficiency. Under subsurface conditions, the injection of nitrate and <span class="hlt">Fe</span> (II) as the electron acceptor and donor allows bacteria to grow. The reaction products include minerals such as <span class="hlt">Fe</span>(OH)3 and nitrogen containing gases. These reaction products can have large impact on oil and reservoir properties and can enhance the recovery of trapped oil. This work aims to understand the <span class="hlt">Fe</span>(II) oxidation by nitrate under conditions relevant to MEOR. Reactive transport <span class="hlt">modeling</span> is used to simulate the fluid flow, transport, and reactions involved in this process. Here we developed a complex reactive network for microbial mediated nitrate-dependent <span class="hlt">Fe</span> (II) oxidation that involves both thermodynamic controlled aqueous reactions and kinetic controlled <span class="hlt">Fe</span> (II) mineral reaction. Reactive transport <span class="hlt">modeling</span> is used to understand and quantify the coupling between flow, transport, and reaction processes. Our results identify key parameter controls those are important for the alteration of permeability profile under field conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3843950','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3843950"><span>Hydrogen Activation by Biomimetic [Ni<span class="hlt">Fe</span>]-Hydrogenase <span class="hlt">Model</span> Containing Protected Cyanide Cofactors</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Manor, Brian C.; Rauchfuss, Thomas B.</p> <p>2013-01-01</p> <p>Described are experiments that allow incorporation of cyanide cofactors and hydride substrate into active site <span class="hlt">models</span> [Ni<span class="hlt">Fe</span>]-hydrogenases (H2ases). Complexes of the type (CO)2(CN)2<span class="hlt">Fe</span>(pdt)Ni(dxpe), (dxpe = dppe, 1; dxpe = dcpe, 2) bind the Lewis acid B(C6F5)3 (BArF3) to give the adducts (CO)2(CNBArF3)2<span class="hlt">Fe</span>(pdt)Ni(dxpe), (1(BArF3)2, 2(BArF3)2). Upon decarbonylation using amine oxides, these adducts react with H2 to give hydrido derivatives Et4N[(CO)(CNBArF3)2<span class="hlt">Fe</span>(H)(pdt)Ni(dxpe)], (dxpe = dppe, Et4N[H3(BArF3)2]; dxpe = dcpe, Et4N[H4(BArF3)2]). Crystallographic analysis shows that Et4N[H3(BArF3)2] generally resembles the active site of the enzyme in the reduced, hydride-containing states (Ni-C/R). The <span class="hlt">Fe</span>-H…Ni center is unsymmetrical with r<span class="hlt">Fe</span>-H = 1.51(3) and rNi-H = 1.71(3) Å. Both crystallographic and 19F NMR analysis show that the CNBArF3− ligands occupy basal and apical sites. Unlike cationic Ni-<span class="hlt">Fe</span> hydrides, [H3(BArF3)2]− and [H4(BArF3)2]− oxidize at mild potentials, near the Fc+/0 couple. Electrochemical measurements indicate that in the presence of base, [H3(BArF3)2]− catalyzes the oxidation of H2. NMR evidence indicates dihydrogen bonding between these anionic hydrides and ammonium salts, which is relevant to the mechanism of hydrogenogenesis. In the case of Et4N[H3(BArF3)2], strong acids such as HCl induce H2 release to give the chloride Et4N[(CO)(CNBArF3)2<span class="hlt">Fe</span>(pdt)(Cl)Ni(dppe)]. PMID:23899049</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1399491-applicability-analysis-validation-evidence-biomedical-computational-models','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1399491-applicability-analysis-validation-evidence-biomedical-computational-models"><span>Applicability Analysis of <span class="hlt">Validation</span> Evidence for Biomedical Computational <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Pathmanathan, Pras; Gray, Richard A.; Romero, Vicente J.</p> <p></p> <p>Computational <span class="hlt">modeling</span> has the potential to revolutionize medicine the way it transformed engineering. However, despite decades of work, there has only been limited progress to successfully translate <span class="hlt">modeling</span> research to patient care. One major difficulty which often occurs with biomedical computational <span class="hlt">models</span> is an inability to perform <span class="hlt">validation</span> in a setting that closely resembles how the <span class="hlt">model</span> will be used. For example, for a biomedical <span class="hlt">model</span> that makes in vivo clinically relevant predictions, direct <span class="hlt">validation</span> of predictions may be impossible for ethical, technological, or financial reasons. Unavoidable limitations inherent to the <span class="hlt">validation</span> process lead to challenges in evaluating the credibilitymore » of biomedical <span class="hlt">model</span> predictions. Therefore, when evaluating biomedical <span class="hlt">models</span>, it is critical to rigorously assess applicability, that is, the relevance of the computational <span class="hlt">model</span>, and its <span class="hlt">validation</span> evidence to the proposed context of use (COU). However, there are no well-established methods for assessing applicability. In this paper, we present a novel framework for performing applicability analysis and demonstrate its use with a medical device computational <span class="hlt">model</span>. The framework provides a systematic, step-by-step method for breaking down the broad question of applicability into a series of focused questions, which may be addressed using supporting evidence and subject matter expertise. The framework can be used for <span class="hlt">model</span> justification, <span class="hlt">model</span> assessment, and <span class="hlt">validation</span> planning. While motivated by biomedical <span class="hlt">models</span>, it is relevant to a broad range of disciplines and underlying physics. Finally, the proposed applicability framework could help overcome some of the barriers inherent to <span class="hlt">validation</span> of, and aid clinical implementation of, biomedical <span class="hlt">models</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1399491-applicability-analysis-validation-evidence-biomedical-computational-models','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1399491-applicability-analysis-validation-evidence-biomedical-computational-models"><span>Applicability Analysis of <span class="hlt">Validation</span> Evidence for Biomedical Computational <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Pathmanathan, Pras; Gray, Richard A.; Romero, Vicente J.; ...</p> <p>2017-09-07</p> <p>Computational <span class="hlt">modeling</span> has the potential to revolutionize medicine the way it transformed engineering. However, despite decades of work, there has only been limited progress to successfully translate <span class="hlt">modeling</span> research to patient care. One major difficulty which often occurs with biomedical computational <span class="hlt">models</span> is an inability to perform <span class="hlt">validation</span> in a setting that closely resembles how the <span class="hlt">model</span> will be used. For example, for a biomedical <span class="hlt">model</span> that makes in vivo clinically relevant predictions, direct <span class="hlt">validation</span> of predictions may be impossible for ethical, technological, or financial reasons. Unavoidable limitations inherent to the <span class="hlt">validation</span> process lead to challenges in evaluating the credibilitymore » of biomedical <span class="hlt">model</span> predictions. Therefore, when evaluating biomedical <span class="hlt">models</span>, it is critical to rigorously assess applicability, that is, the relevance of the computational <span class="hlt">model</span>, and its <span class="hlt">validation</span> evidence to the proposed context of use (COU). However, there are no well-established methods for assessing applicability. In this paper, we present a novel framework for performing applicability analysis and demonstrate its use with a medical device computational <span class="hlt">model</span>. The framework provides a systematic, step-by-step method for breaking down the broad question of applicability into a series of focused questions, which may be addressed using supporting evidence and subject matter expertise. The framework can be used for <span class="hlt">model</span> justification, <span class="hlt">model</span> assessment, and <span class="hlt">validation</span> planning. While motivated by biomedical <span class="hlt">models</span>, it is relevant to a broad range of disciplines and underlying physics. Finally, the proposed applicability framework could help overcome some of the barriers inherent to <span class="hlt">validation</span> of, and aid clinical implementation of, biomedical <span class="hlt">models</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27230264','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27230264"><span>Cross-<span class="hlt">validation</span> to select Bayesian hierarchical <span class="hlt">models</span> in phylogenetics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duchêne, Sebastián; Duchêne, David A; Di Giallonardo, Francesca; Eden, John-Sebastian; Geoghegan, Jemma L; Holt, Kathryn E; Ho, Simon Y W; Holmes, Edward C</p> <p>2016-05-26</p> <p>Recent developments in Bayesian phylogenetic <span class="hlt">models</span> have increased the range of inferences that can be drawn from molecular sequence data. Accordingly, <span class="hlt">model</span> selection has become an important component of phylogenetic analysis. Methods of <span class="hlt">model</span> selection generally consider the likelihood of the data under the <span class="hlt">model</span> in question. In the context of Bayesian phylogenetics, the most common approach involves estimating the marginal likelihood, which is typically done by integrating the likelihood across <span class="hlt">model</span> parameters, weighted by the prior. Although this method is accurate, it is sensitive to the presence of improper priors. We explored an alternative approach based on cross-<span class="hlt">validation</span> that is widely used in evolutionary analysis. This involves comparing <span class="hlt">models</span> according to their predictive performance. We analysed simulated data and a range of viral and bacterial data sets using a cross-<span class="hlt">validation</span> approach to compare a variety of molecular clock and demographic <span class="hlt">models</span>. Our results show that cross-<span class="hlt">validation</span> can be effective in distinguishing between strict- and relaxed-clock <span class="hlt">models</span> and in identifying demographic <span class="hlt">models</span> that allow growth in population size over time. In most of our empirical data analyses, the <span class="hlt">model</span> selected using cross-<span class="hlt">validation</span> was able to match that selected using marginal-likelihood estimation. The accuracy of cross-<span class="hlt">validation</span> appears to improve with longer sequence data, particularly when distinguishing between relaxed-clock <span class="hlt">models</span>. Cross-<span class="hlt">validation</span> is a useful method for Bayesian phylogenetic <span class="hlt">model</span> selection. This method can be readily implemented even when considering complex <span class="hlt">models</span> where selecting an appropriate prior for all parameters may be difficult.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SMaS...26j5019K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SMaS...26j5019K"><span><span class="hlt">Modeling</span> of magnetic hystereses in soft MREs filled with Nd<span class="hlt">Fe</span>B particles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kalina, K. A.; Brummund, J.; Metsch, P.; Kästner, M.; Borin, D. Yu; Linke, J. M.; Odenbach, S.</p> <p>2017-10-01</p> <p>Herein, we investigate the structure-property relationships of soft magnetorheological elastomers (MREs) filled with remanently magnetizable particles. The study is motivated from experimental results which indicate a large difference between the magnetization loops of soft MREs filled with Nd<span class="hlt">Fe</span>B particles and the loops of such particles embedded in a comparatively stiff matrix, e.g. an epoxy resin. We present a microscale <span class="hlt">model</span> for MREs based on a general continuum formulation of the magnetomechanical boundary value problem which is <span class="hlt">valid</span> for finite strains. In particular, we develop an energetically consistent constitutive <span class="hlt">model</span> for the hysteretic magnetization behavior of the magnetically hard particles. The microstructure is discretized and the problem is solved numerically in terms of a coupled nonlinear finite element approach. Since the local magnetic and mechanical fields are resolved explicitly inside the heterogeneous microstructure of the MRE, our <span class="hlt">model</span> also accounts for interactions of particles close to each other. In order to connect the microscopic fields to effective macroscopic quantities of the MRE, a suitable computational homogenization scheme is used. Based on this <span class="hlt">modeling</span> approach, it is demonstrated that the observable macroscopic behavior of the considered MREs results from the rotation of the embedded particles. Furthermore, the performed numerical simulations indicate that the reversion of the sample’s magnetization occurs due to a combination of particle rotations and internal domain conversion processes. All of our simulation results obtained for such materials are in a good qualitative agreement with the experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005ApJS..158..230M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005ApJS..158..230M"><span>Accurate Wavelength Measurements and <span class="hlt">Modeling</span> of <span class="hlt">Fe</span> XV to <span class="hlt">Fe</span> XIX Spectra Recorded in High-Density Plasmas between 13.5 and 17 Å</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>May, M. J.; Beiersdorfer, P.; Dunn, J.; Jordan, N.; Hansen, S. B.; Osterheld, A. L.; Faenov, A. Ya.; Pikuz, T. A.; Skobelev, I. Yu.; Flora, F.; Bollanti, S.; Di Lazzaro, P.; Murra, D.; Reale, A.; Reale, L.; Tomassetti, G.; Ritucci, A.; Francucci, M.; Martellucci, S.; Petrocelli, G.</p> <p>2005-06-01</p> <p>Iron spectra have been recorded from plasmas created at three different laser plasma facilities: the Tor Vergata University laser in Rome (Italy), the Hercules laser at ENEA in Frascati (Italy), and the Compact Multipulse Terawatt (COMET) laser at LLNL in California (USA). The measurements provide a means of identifying dielectronic satellite lines from <span class="hlt">Fe</span> XVI and <span class="hlt">Fe</span> XV in the vicinity of the strong 2p-->3d transitions of <span class="hlt">Fe</span> XVII. About 80 Δn>=1 lines of <span class="hlt">Fe</span> XV (Mg-like) to <span class="hlt">Fe</span> XIX (O-like) were recorded between 13.8 and 17.1 Å with a high spectral resolution (λ/Δλ~4000) about 30 of these lines are from <span class="hlt">Fe</span> XVI and <span class="hlt">Fe</span> XV. The laser-produced plasmas had electron temperatures between 100 and 500 eV and electron densities between 1020 and 1022 cm-3. The Hebrew University Lawrence Livermore Atomic Code (HULLAC) was used to calculate the atomic structure and atomic rates for <span class="hlt">Fe</span> XV-XIX. HULLAC was used to calculate synthetic line intensities at Te=200 eV and ne=1021 cm-3 for three different conditions to illustrate the role of opacity: optically thin plasmas with no excitation-autoionization/dielectronic recombination (EA/DR) contributions to the line intensities, optically thin plasmas that included EA/DR contributions to the line intensities, and optically thick plasmas (optical depth ~200 μm) that included EA/DR contributions to the line intensities. The optically thick simulation best reproduced the recorded spectrum from the Hercules laser. However, some discrepancies between the <span class="hlt">modeling</span> and the recorded spectra remain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeCoA.165...44S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeCoA.165...44S"><span>Fractionation of <span class="hlt">Fe</span> isotopes during <span class="hlt">Fe</span>(II) oxidation by a marine photoferrotroph is controlled by the formation of organic <span class="hlt">Fe</span>-complexes and colloidal <span class="hlt">Fe</span> fractions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swanner, Elizabeth D.; Wu, Wenfang; Schoenberg, Ronny; Byrne, James; Michel, F. Marc; Pan, Yongxin; Kappler, Andreas</p> <p>2015-09-01</p> <p>Much interest exists in finding mineralogical, organic, morphological, or isotopic biosignatures for <span class="hlt">Fe</span>(II)-oxidizing bacteria (<span class="hlt">Fe</span>OB) that are retained in <span class="hlt">Fe</span>-rich sediments, which could indicate the activity of these organisms in <span class="hlt">Fe</span>-rich seawater, more common in the Precambrian Era. To date, the effort to establish a clear <span class="hlt">Fe</span> isotopic signature in <span class="hlt">Fe</span> minerals produced by <span class="hlt">Fe</span>(II)-oxidizing metabolisms has been thwarted by the large kinetic fractionation incurred as freshly oxidized aqueous <span class="hlt">Fe</span>(III) rapidly precipitates as <span class="hlt">Fe</span>(III) (oxyhydr)oxide minerals at near neutral pH. The <span class="hlt">Fe</span>(III) (oxyhydr)oxide minerals resulting from abiotic <span class="hlt">Fe</span>(II) oxidation are isotopically heavy compared to the <span class="hlt">Fe</span>(II) precursor and are not clearly distinguishable from minerals formed by <span class="hlt">Fe</span>OB isotopically. However, in marine hydrothermal systems and <span class="hlt">Fe</span>(II)-rich springs the minerals formed are often isotopically lighter than expected considering the fraction of <span class="hlt">Fe</span>(II) that has been oxidized and experimentally-determined fractionation factors. We measured the <span class="hlt">Fe</span> isotopic composition of aqueous <span class="hlt">Fe</span> (Feaq) and the final <span class="hlt">Fe</span> mineral (Feppt) produced in batch experiment using the marine <span class="hlt">Fe</span>(II)-oxidizing phototroph Rhodovulum iodosum. The δ56Feaq data are best described by a kinetic fractionation <span class="hlt">model</span>, while the evolution of δ56Feppt appears to be controlled by a separate fractionation process. We propose that soluble <span class="hlt">Fe</span>(III), and <span class="hlt">Fe</span>(II) and <span class="hlt">Fe</span>(III) extracted from the Feppt may act as intermediates between <span class="hlt">Fe</span>(II) oxidation and <span class="hlt">Fe</span>(III) precipitation. Based on 57<span class="hlt">Fe</span> Mössbauer spectroscopy, extended X-ray absorption fine structure (EXAFS) spectroscopy, and X-ray total scattering, we suggests these <span class="hlt">Fe</span> phases, collectively <span class="hlt">Fe</span>(II/III)interm, may consist of organic-ligand bound, sorbed, and/or colloidal <span class="hlt">Fe</span>(II) and <span class="hlt">Fe</span>(III) mineral phases that are isotopically lighter than the final <span class="hlt">Fe</span>(III) mineral product. Similar intermediate phases, formed in response to organic carbon produced by <span class="hlt">Fe</span>OB and inorganic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MRE.....4k6518B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MRE.....4k6518B"><span>Mechanical properties of <span class="hlt">Fe</span> rich <span class="hlt">Fe</span>-Si alloys: ab initio local bulk-modulus viewpoint</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhattacharya, Somesh Kr; Kohyama, Masanori; Tanaka, Shingo; Shiihara, Yoshinori; Saengdeejing, Arkapol; Chen, Ying; Mohri, Tetsuo</p> <p>2017-11-01</p> <p><span class="hlt">Fe</span>-rich <span class="hlt">Fe</span>-Si alloys show peculiar bulk-modulus changes depending on the Si concentration in the range of 0-15 at.%Si. In order to clarify the origin of this phenomenon, we have performed density-functional theory calculations of supercells of <span class="hlt">Fe</span>-Si alloy <span class="hlt">models</span> with various Si concentrations. We have applied our recent techniques of ab initio local energy and local stress, by which we can obtain a local bulk modulus of each atom or atomic group as a local constituent of the cell-averaged bulk modulus. A2-phase alloy <span class="hlt">models</span> are constructed by introducing Si substitution into bcc <span class="hlt">Fe</span> as uniformly as possible so as to prevent mutual neighboring, while higher Si concentrations over 6.25 at.%Si lead to contacts between Si<span class="hlt">Fe</span>8 cubic clusters via sharing corner <span class="hlt">Fe</span> atoms. For 12.5 at.%Si, in addition to an A2 <span class="hlt">model</span>, we deal with partial D03 <span class="hlt">models</span> containing local D03-like layers consisting of edge-shared Si<span class="hlt">Fe</span>8 cubic clusters. For the cell-averaged bulk modulus, we have successfully reproduced the Si-concentration dependence as a monotonic decrease until 11.11 at.%Si and a recovery at 12.5 at.%Si. The analysis of local bulk moduli of Si<span class="hlt">Fe</span>8 cubic clusters and <span class="hlt">Fe</span> regions is effective to understand the variations of the cell-averaged bulk modulus. The local bulk moduli of <span class="hlt">Fe</span> regions become lower for increasing Si concentration, due to the suppression of bulk-like d-d bonding states in narrow <span class="hlt">Fe</span> regions. For higher Si concentrations till 11.11 at.%Si, corner-shared contacts or 1D chains of Si<span class="hlt">Fe</span>8 clusters lead to remarkable reduction of local bulk moduli of the clusters. At 12 at.%Si, on the other hand, two- or three-dimensional arrangements of corner- or edge-shared Si<span class="hlt">Fe</span>8 cubic clusters show greatly enhanced local bulk moduli, due to quite different bonding nature with much stronger p-d hybridization. The relation among the local bulk moduli, local electronic and magnetic structures, and local configurations such as connectivity of Si<span class="hlt">Fe</span>8 clusters and <span class="hlt">Fe</span>-region sizes has been</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21843679','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21843679"><span>Oxidase-functionalized <span class="hlt">Fe</span>(3)O(4) nanoparticles for fluorescence sensing of specific substrate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Cheng-Hao; Tseng, Wei-Lung</p> <p>2011-10-03</p> <p>This study reports the development of a reusable, single-step system for the detection of specific substrates using oxidase-functionalized <span class="hlt">Fe</span>(3)O(4) nanoparticles (NPs) as a bienzyme system and using amplex ultrared (AU) as a fluorogenic substrate. In the presence of H(2)O(2), the reaction pH between <span class="hlt">Fe</span>(3)O(4) NPs and AU was similar to the reaction of oxidase and the substrate. The catalytic activity of <span class="hlt">Fe</span>(3)O(4) NPs with AU was nearly unchanged following modification with poly(diallyldimethylammonium chloride) (PDDA). Based on these features, we prepared a composite of PDDA-modified <span class="hlt">Fe</span>(3)O(4) NPs and oxidase for the quantification of specific substrates through the H(2)O(2)-mediated oxidation of AU. By monitoring fluorescence intensity at 587 nm of oxidized AU, the minimum detectable concentrations of glucose, galactose, and choline were found to be 3, 2, and 20 μM using glucose oxidase-<span class="hlt">Fe</span>(3)O(4), galactose oxidase-<span class="hlt">Fe</span>(3)O(4), and choline oxidase-<span class="hlt">Fe</span>(3)O(4) composites, respectively. The identification of glucose in blood was selected as the <span class="hlt">model</span> to <span class="hlt">validate</span> the applicability of this proposed method. Copyright © 2011 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26154158','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26154158"><span>Dissociative Recombination of <span class="hlt">Fe</span>O(+) with Electrons: Implications for Plasma Layers in the Ionosphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bones, D L; Plane, J M C; Feng, W</p> <p>2016-03-10</p> <p>The dissociative recombination (DR) of <span class="hlt">Fe</span>O(+) ions with electrons has been studied in a flowing afterglow reactor. <span class="hlt">Fe</span>O(+) was generated by the pulsed laser ablation of a solid <span class="hlt">Fe</span> target, and then entrained in an Ar(+) ion/electron plasma where the absolute electron density was measured using a Langmuir probe. A kinetic <span class="hlt">model</span> describing gas-phase chemistry and diffusion to the reactor walls was fitted to the experimental data, yielding a DR rate coefficient at 298 K of k(<span class="hlt">Fe</span>O(+) + e(-)) = (5.5 ± 1.0) × 10(-7) cm(3) molecule(-1) s(-1), where the quoted uncertainty is at the 2σ level. <span class="hlt">Fe</span>(+) ions in the lower thermosphere are oxidized by O3 to <span class="hlt">Fe</span>O(+), and this DR reaction is shown to provide a more important route for neutralizing <span class="hlt">Fe</span>(+) below 110 km than the radiative/dielectronic recombination of <span class="hlt">Fe</span>(+) with electrons. The experimental system was first <span class="hlt">validated</span> by measuring two other DR reaction rate coefficients: k(O2(+) + e(-)) = (2.0 ± 0.4) × 10(-7) and k(N2O(+) + e(-)) = (3.3 ± 0.8) × 10(-7) cm(3) molecule(-1) s(-1), which are in good agreement with the recent literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18433827','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18433827"><span>Observed and <span class="hlt">modeled</span> seasonal trends in dissolved and particulate Cu, <span class="hlt">Fe</span>, Mn, and Zn in a mining-impacted stream.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Butler, Barbara A; Ranville, James F; Ross, Philippe E</p> <p>2008-06-01</p> <p>North Fork Clear Creek (NFCC) in Colorado, an acid-mine drainage (AMD) impacted stream, was chosen to examine the distribution of dissolved and particulate Cu, <span class="hlt">Fe</span>, Mn, and Zn in the water column, with respect to seasonal hydrologic controls. NFCC is a high-gradient stream with discharge directly related to snowmelt and strong seasonal storms. Additionally, conditions in the stream cause rapid precipitation of large amounts of hydrous iron oxides (HFO) that sequester metals. Because AMD-impacted systems are complex, geochemical <span class="hlt">modeling</span> may assist with predictions and/or confirmations of processes occurring in these environments. This research used Visual-MINTEQ to determine if field data collected over a two and one-half year study would be well represented by <span class="hlt">modeling</span> with a currently existing <span class="hlt">model</span>, while limiting the number of processes <span class="hlt">modeled</span> and without modifications to the existing <span class="hlt">model</span>'s parameters. Observed distributions between dissolved and particulate phases in the water column varied greatly among the metals, with average dissolved fractions being >90% for Mn, approximately 75% for Zn, approximately 30% for Cu, and <10% for <span class="hlt">Fe</span>. A strong seasonal trend was observed for the metals predominantly in the dissolved phase (Mn and Zn), with increasing concentrations during base-flow conditions and decreasing concentrations during spring-runoff. This trend was less obvious for Cu and <span class="hlt">Fe</span>. Within hydrologic seasons, storm events significantly influenced in-stream metals concentrations. The most simplified <span class="hlt">modeling</span>, using solely sorption to HFO, gave predicted percentage particulate Cu results for most samples to within a factor of two of the measured values, but <span class="hlt">modeling</span> data were biased toward over-prediction. About one-half of the percentage particulate Zn data comparisons fell within a factor of two, with the remaining data being under-predicted. Slightly more complex <span class="hlt">modeling</span>, which included dissolved organic carbon (DOC) as a solution phase ligand</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1261385-effects-two-temperature-model-cascade-evolution-ni-nife','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1261385-effects-two-temperature-model-cascade-evolution-ni-nife"><span>Effects of two-temperature <span class="hlt">model</span> on cascade evolution in Ni and Ni<span class="hlt">Fe</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Samolyuk, German D.; Xue, Haizhou; Bei, Hongbin; ...</p> <p>2016-07-05</p> <p>We perform molecular dynamics simulations of Ni ion cascades in Ni and equiatomic Ni<span class="hlt">Fe</span> under the following conditions: (a) classical molecular dynamics (MD) simulations without consideration of electronic energy loss, (b) classical MD simulations with the electronic stopping included, and (c) using the coupled two-temperature MD (2T-MD) <span class="hlt">model</span> that incorporates both the electronic stopping and the electron-phonon interactions. Our results indicate that the electronic effects are more profound in the higher-energy cascades, and that the 2T-MD <span class="hlt">model</span> results in a smaller amount of surviving damage and smaller defect clusters, while less damage is produced in Ni<span class="hlt">Fe</span> than in Ni.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatCh...8.1054B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatCh...8.1054B"><span>Nickel-centred proton reduction catalysis in a <span class="hlt">model</span> of [Ni<span class="hlt">Fe</span>] hydrogenase</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brazzolotto, Deborah; Gennari, Marcello; Queyriaux, Nicolas; Simmons, Trevor R.; Pécaut, Jacques; Demeshko, Serhiy; Meyer, Franc; Orio, Maylis; Artero, Vincent; Duboc, Carole</p> <p>2016-11-01</p> <p>Hydrogen production through water splitting is one of the most promising solutions for the storage of renewable energy. [Ni<span class="hlt">Fe</span>] hydrogenases are organometallic enzymes containing nickel and iron centres that catalyse hydrogen evolution with performances that rival those of platinum. These enzymes provide inspiration for the design of new molecular catalysts that do not require precious metals. However, all heterodinuclear Ni<span class="hlt">Fe</span> <span class="hlt">models</span> reported so far do not reproduce the Ni-centred reactivity found at the active site of [Ni<span class="hlt">Fe</span>] hydrogenases. Here, we report a structural and functional Ni<span class="hlt">Fe</span> mimic that displays reactivity at the Ni site. This is shown by the detection of two catalytic intermediates that reproduce structural and electronic features of the Ni-L and Ni-R states of the enzyme during catalytic turnover. Under electrocatalytic conditions, this mimic displays high rates for H2 evolution (second-order rate constant of 2.5 × 104 M-1 s-1 turnover frequency of 250 s-1 at 10 mM H+ concentration) from mildly acidic solutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5493981','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5493981"><span>Nickel centred H+ reduction catalysis in a <span class="hlt">model</span> of [Ni<span class="hlt">Fe</span>] Hydrogenase</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Brazzolotto, Deborah; Gennari, Marcello; Queyriaux, Nicolas; Simmons, Trevor R.; Pécaut, Jacques; Demeshko, Serhiy; Meyer, Franc; Orio, Maylis; Artero, Vincent; Duboc, Carole</p> <p>2017-01-01</p> <p>Hydrogen production through water splitting is one of the most promising solutions for the storage of renewable energy. [Ni<span class="hlt">Fe</span>] hydrogenases are organometallic enzymes containing nickel and iron centers that catalyze hydrogen evolution with performances that rival those of platinum. These enzymes provide inspiration for the design of new molecular catalysts that do not require precious metals. However, all heterodinuclear Ni<span class="hlt">Fe</span> <span class="hlt">models</span> reported so far do not reproduce the Ni-centered reactivity found at the active site of [Ni<span class="hlt">Fe</span>] hydrogenases. Here we report a structural and functional Ni<span class="hlt">Fe</span> mimic that displays reactivity at the Ni site. This is shown by the detection of two catalytic intermediates that reproduce structural and electronic features of the Ni-L and Ni-R states of the enzyme during catalytic turnover. Under electrocatalytic conditions, this mimic displays high rates for H2 evolution (second order rate constant of 2.5 104 M-1s-1; turnover frequency of 225 s-1 at 10 mM H+ concentration) from mildly acidic solutions. PMID:27768098</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25303871','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25303871"><span>Isolation and in silico analysis of <span class="hlt">Fe</span>-superoxide dismutase in the cyanobacterium Nostoc commune.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kesheri, Minu; Kanchan, Swarna; Richa; Sinha, Rajeshwar P</p> <p>2014-12-15</p> <p>Cyanobacteria are known to endure various stress conditions due to the inbuilt potential for oxidative stress alleviation owing to the presence of an array of antioxidants. The present study shows that Antarctic cyanobacterium Nostoc commune possesses two antioxidative enzymes viz., superoxide dismutase (SOD) and catalase that jointly cope with environmental stresses prevailing at its natural habitat. Native-PAGE analysis illustrates the presence of a single prominent isoform recognized as <span class="hlt">Fe</span>-SOD and three distinct isoforms of catalase. The protein sequence of <span class="hlt">Fe</span>-SOD in N. commune retrieved from NCBI protein sequence database was used for in silico analysis. 3D structure of N. commune was predicted by comparative <span class="hlt">modeling</span> using <span class="hlt">MODELLER</span> 9v11. Further, this <span class="hlt">model</span> was <span class="hlt">validated</span> for its quality by Ramachandran plot, ERRAT, Verify 3D and ProSA-web which revealed good structure quality of the <span class="hlt">model</span>. Multiple sequence alignment showed high conservation in N and C-terminal domain regions along with all metal binding positions in <span class="hlt">Fe</span>-SOD which were also found to be highly conserved in all 28 cyanobacterial species under study, including N. commune. In silico prediction of isoelectric point and molecular weight of <span class="hlt">Fe</span>-SOD was found to be 5.48 and 22,342.98Da respectively. The phylogenetic tree revealed that among 28 cyanobacterial species, <span class="hlt">Fe</span>-SOD in N. commune was the closest evolutionary homolog of <span class="hlt">Fe</span>-SOD in Nostoc punctiforme as evident by strong bootstrap value. Thus, N. commune may serve as a good biological <span class="hlt">model</span> for studies related to survival of life under extreme conditions prevailing at the Antarctic region. Moreover cyanobacteria may be exploited for biochemical and biotechnological applications of enzymatic antioxidants. Copyright © 2014 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA626563','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA626563"><span><span class="hlt">Model</span> <span class="hlt">Validation</span> Against The <span class="hlt">Modelers</span>’ Data Archive</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-08-01</p> <p>completion of the planned Jack Rabbit 2 field trials. The relevant task for the effort addressed here is Task 4 of the current Interagency Agreement, as...readily simulates the Prairie Grass sulfur dioxide plumes. Also, Jack Rabbit II field trials are set to be completed during FY16. Once these data are...available, they will also be used to <span class="hlt">validate</span> the combined <span class="hlt">models</span>. This <span class="hlt">validation</span> may prove to be more useful, as the Jack Rabbit II will release</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1953c0117S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1953c0117S"><span>Effect of 120 MeV 28Si9+ ion irradiation on structural and magnetic properties of Ni<span class="hlt">Fe</span>2O4 and Ni0.5Zn0.5<span class="hlt">Fe</span>2O4</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sharma, R.; Raghuvanshi, S.; Satalkar, M.; Kane, S. N.; Tatarchuk, T. R.; Mazaleyrat, F.</p> <p>2018-05-01</p> <p>Ni<span class="hlt">Fe</span>2O4, Ni0.5Zn0.5<span class="hlt">Fe</span>2O4 samples were synthesized using sol-gel auto combustion method, and irradiated by using 120 MeV 28Si9+ ion with ion fluence of 1×1012 ions/cm2. Characterization of pristine, irradiated samples were done using X-Ray Diffraction (XRD), Field Emission Scanning Microscopy (<span class="hlt">FE</span>-SEM), Energy Dispersive X-ray Analysis (EDAX) and Vibrating Sample Magnetometer (VSM). XRD <span class="hlt">validates</span> the single phase nature of pristine, irradiated Ni- Zn nano ferrite except for Ni ferrite (pristine, irradiated) where secondary phases of α-<span class="hlt">Fe</span>2O3 and Ni is observed. <span class="hlt">FE</span>- SEM images of pristine Ni, Ni-Zn ferrite show inhomogeneous nano-range particle size distribution. Presence of diamagnetic ion (Zn2+) in Ni<span class="hlt">Fe</span>2O4 increases oxygen positional parameter (u 4¯3m ), experimental, theoretical saturation magnetization (Msexp., Msth.), while decreases the grain size (Ds) and coercivity (Hc). With irradiation Msexp., Msth. increases but not much change are observed in Hc. New antistructure <span class="hlt">modeling</span> for the pristine, irradiated Ni and Ni-Zn ferrite samples was used for describing the surface active centers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/15016764','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/15016764"><span>Accurate wavelength measurements and <span class="hlt">modeling</span> of <span class="hlt">Fe</span>XV to <span class="hlt">Fe</span>XIX spectra recorded in high density plasmas between 13.5 to 17 A.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>May, M; Beiersdorfer, P; Dunn, J</p> <p></p> <p>Iron spectra have been recorded from plasmas created at three different laser plasma facilities, the Tor Vergata University laser in Rome (Italy), the Hercules laser at ENEA in Frascati (Italy), and the Compact Multipulse Terawatt (COMET) laser at LLNL in California (USA). The measurements provide a means of identifying dielectronic satellite lines from <span class="hlt">Fe</span>XVI and <span class="hlt">Fe</span>XV in the vicinity of the strong 2p {yields} 3d transitions of <span class="hlt">Fe</span>XVII. About 80 {Delta}n {ge} 1 lines of <span class="hlt">Fe</span>XV (Mg-like) to <span class="hlt">Fe</span>XIX (O-like) were recorded between 13.8 to 17.1 {angstrom} with a high spectral resolution ({lambda}/{Delta}{lambda} {approx} 4000), about thirty of these linesmore » are from <span class="hlt">Fe</span>XVI and <span class="hlt">Fe</span>XV. The laser produced plasmas had electron temperatures between 100 to 500 eV and electron densities between 10{sup 20} to 10{sup 22} cm{sup -3}. The Hebrew University Lawrence Livermore Atomic Code (HULLAC) was used to calculate the atomic structure and atomic rates for <span class="hlt">Fe</span>XV to <span class="hlt">Fe</span>XIX. HULLAC was used to calculate synthetic line intensities at T{sub e} = 200 eV and n{sub e} = 10{sup 21}cm{sup -3} for three different conditions to illustrate the role of opacity: optically thin plasmas with no excitation-autoionization/dielectronic recombination (EA/DR) contributions to the line intensities, optically thin plasmas that included EA/DR contributions to the line intensities, and optically thick plasmas (optical depth {approx} 200 {micro}m) that included EA/DR contributions to the line intensities. The optically thick simulation best reproduced the recorded spectrum from the Hercules laser. However some discrepancies between the <span class="hlt">modeling</span> and the recorded spectra remain.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011icov.conf..801S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011icov.conf..801S"><span><span class="hlt">FE</span> <span class="hlt">Modelling</span> of the Fluid-Structure-Acoustic Interaction for the Vocal Folds Self-Oscillation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Švancara, Pavel; Horáček, J.; Hrůza, V.</p> <p></p> <p>The flow induced self-oscillation of the human vocal folds in interaction with acoustic processes in the simplified vocal tract <span class="hlt">model</span> was explored by three-dimensional (3D) finite element (<span class="hlt">FE</span>) <span class="hlt">model</span>. Developed <span class="hlt">FE</span> <span class="hlt">model</span> includes vocal folds pretension before phonation, large deformations of the vocal fold tissue, vocal folds contact, fluid-structure interaction, morphing the fluid mesh according the vocal folds motion (Arbitrary Lagrangian-Eulerian approach), unsteady viscous compressible airflow described by the Navier-Stokes equations and airflow separation during the glottis closure. Iterative partitioned approach is used for <span class="hlt">modelling</span> the fluid-structure interaction. Computed results prove that the developed <span class="hlt">model</span> can be used for simulation of the vocal folds self-oscillation and resulting acoustic waves. The developed <span class="hlt">model</span> enables to numerically simulate an influence of some pathological changes in the vocal fold tissue on the voice production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20659272','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20659272"><span><span class="hlt">Modeling</span> complex treatment strategies: construction and <span class="hlt">validation</span> of a discrete event simulation <span class="hlt">model</span> for glaucoma.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Gestel, Aukje; Severens, Johan L; Webers, Carroll A B; Beckers, Henny J M; Jansonius, Nomdo M; Schouten, Jan S A G</p> <p>2010-01-01</p> <p>Discrete event simulation (DES) <span class="hlt">modeling</span> has several advantages over simpler <span class="hlt">modeling</span> techniques in health economics, such as increased flexibility and the ability to <span class="hlt">model</span> complex systems. Nevertheless, these benefits may come at the cost of reduced transparency, which may compromise the <span class="hlt">model</span>'s face <span class="hlt">validity</span> and credibility. We aimed to produce a transparent report on the construction and <span class="hlt">validation</span> of a DES <span class="hlt">model</span> using a recently developed <span class="hlt">model</span> of ocular hypertension and glaucoma. Current evidence of associations between prognostic factors and disease progression in ocular hypertension and glaucoma was translated into DES <span class="hlt">model</span> elements. The <span class="hlt">model</span> was extended to simulate treatment decisions and effects. Utility and costs were linked to disease status and treatment, and clinical and health economic outcomes were defined. The <span class="hlt">model</span> was <span class="hlt">validated</span> at several levels. The soundness of design and the plausibility of input estimates were evaluated in interdisciplinary meetings (face <span class="hlt">validity</span>). Individual patients were traced throughout the simulation under a multitude of <span class="hlt">model</span> settings to debug the <span class="hlt">model</span>, and the <span class="hlt">model</span> was run with a variety of extreme scenarios to compare the outcomes with prior expectations (internal <span class="hlt">validity</span>). Finally, several intermediate (clinical) outcomes of the <span class="hlt">model</span> were compared with those observed in experimental or observational studies (external <span class="hlt">validity</span>) and the feasibility of evaluating hypothetical treatment strategies was tested. The <span class="hlt">model</span> performed well in all <span class="hlt">validity</span> tests. Analyses of hypothetical treatment strategies took about 30 minutes per cohort and lead to plausible health-economic outcomes. There is added value of DES <span class="hlt">models</span> in complex treatment strategies such as glaucoma. Achieving transparency in <span class="hlt">model</span> structure and outcomes may require some effort in reporting and <span class="hlt">validating</span> the <span class="hlt">model</span>, but it is feasible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS43B2033G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS43B2033G"><span>Kinetic <span class="hlt">model</span> to explain the effect of ocean warming and acidification on the <span class="hlt">Fe</span>(II) oxidation rate in oligotrophic and eutrophic natural waters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>González-Dávila, M.; Samperio-Ramos, G.; Santana-Casiano, J. M.; Gonzallez, A. G.; Pérez-Almeida, N.</p> <p>2016-12-01</p> <p>The speciation of inorganic <span class="hlt">Fe</span>(II) as a function of the pH and temperature have been <span class="hlt">modeled</span> in order to elucidate the inorganic <span class="hlt">Fe</span>(II) redox behavior over a wide range of scenarios of acidification and global warming of the upper ocean, as well as, changes due to natural ambient fluctuations of pH and temperature. In addition, a kinetic <span class="hlt">modeling</span> approach has been carried out to elucidate the fractional contribution of most kinetically active <span class="hlt">Fe</span>(II) species to the overall oxidation rate to improve our future and present knowledge with respect to redox iron chemistry in the marine systems. The kinetic <span class="hlt">model</span> considers the interactions of <span class="hlt">Fe</span>(II) with the major ions in seawater, including phosphate and silicate and the competition with copper with the ROS. The <span class="hlt">model</span> has been applied to the experimental results in order to describe the effect of temperature and pH in the speciation of <span class="hlt">Fe</span>(II) and to compute the fractional contribution of each <span class="hlt">Fe</span>(II)-specie to the overall oxidation rate. The oxidation rates (kapp) of nanomolar levels of <span class="hlt">Fe</span>(II) have been studied in seawater enriched with nutrients (SWEN) in air saturated conditions. The nutrient effect (nitrate, phosphate and silicate), on the oxidation of <span class="hlt">Fe</span>(II), has been evaluated as a function of pH (7.2-8.2), temperature (5-35 ºC) and salinity (10-37.09). The oxidation of <span class="hlt">Fe</span>(II) was faster in the presence of nutrient with the change in the <span class="hlt">Fe</span>(II) oxidation rates (Δlogkapp) more intensive at higher temperatures over the entire pH range studied. From the <span class="hlt">model</span> it can be observed that the inorganic speciation of <span class="hlt">Fe</span>(II) is controlled largely by pH, either in SW or in SWEN. A greater presence of <span class="hlt">Fe</span>-nutrient reactive species (<span class="hlt">Fe</span>H3SiO4+ and <span class="hlt">Fe</span>PO4-) in SWEN at higher temperatures explained the changes in the oxidation process. The individual oxidation rates by oxygen, for the <span class="hlt">Fe</span>(II) most kinetically active species (<span class="hlt">Fe</span>2+, <span class="hlt">Fe</span>OH+, <span class="hlt">Fe</span>(OH)2, <span class="hlt">Fe</span>CO3(OH)-, <span class="hlt">Fe</span>CO3, <span class="hlt">Fe</span>(CO3)22-, <span class="hlt">Fe</span>H3SiO3+, <span class="hlt">Fe</span>PO4-), were fitted as a function of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97d5118Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97d5118Z"><span>Breakdown of single spin-fluid <span class="hlt">model</span> in the heavily hole-doped superconductor Cs<span class="hlt">Fe</span>2As2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, D.; Li, S. J.; Wang, N. Z.; Li, J.; Song, D. W.; Zheng, L. X.; Nie, L. P.; Luo, X. G.; Wu, T.; Chen, X. H.</p> <p>2018-01-01</p> <p>Although <span class="hlt">Fe</span>-based superconductors are correlated electronic systems with multiorbital, previous nuclear magnetic resonance (NMR) measurement suggests that a single spin-fluid <span class="hlt">model</span> is sufficient to describe its spin behavior. Here, we first observed the breakdown of single spin-fluid <span class="hlt">model</span> in a heavily hole-doped <span class="hlt">Fe</span>-based superconductor Cs<span class="hlt">Fe</span>2As2 by site-selective NMR measurement. At high-temperature regime, both Knight shift and nuclear spin-lattice relaxation at 133Cs and 75As nuclei exhibit distinct temperature-dependent behavior, suggesting the breakdown of the single spin-fluid <span class="hlt">model</span> in Cs<span class="hlt">Fe</span>2As2 . This is ascribed to the coexistence of both localized and itinerant spin degree of freedom at 3 d orbitals, which is consistent with the orbital-selective Mott phase. With decreasing temperature, the single spin-fluid behavior is recovered below T*˜75 K due to a coherent state among 3 d orbitals. The Kondo liquid scenario is proposed to understand the low-temperature coherent state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhyB..536..115F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhyB..536..115F"><span>The microscopic <span class="hlt">model</span> of Bi<span class="hlt">Fe</span>O3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fishman, R. S.</p> <p>2018-05-01</p> <p>Many years and great effort have been spent constructing the microscopic <span class="hlt">model</span> for the room temperature multiferroic Bi<span class="hlt">Fe</span>O3. However, earlier <span class="hlt">models</span> implicitly assumed that the cycloidal wavevector q was confined to one of the three-fold symmetric axes in the hexagonal plane normal to the electric polarization. Because recent measurements indicate that q can be rotated by a magnetic field, it is essential to properly treat the anisotropy that confines q at low fields. We propose that the anisotropy energy -K3S6sin6 θ cos 6 ϕ confines the wavevectors q to the three-fold axis ϕ = 0 and ± 2 π / 3 within the hexagonal plane with θ = π / 2 .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27215928','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27215928"><span>External <span class="hlt">model</span> <span class="hlt">validation</span> of binary clinical risk prediction <span class="hlt">models</span> in cardiovascular and thoracic surgery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hickey, Graeme L; Blackstone, Eugene H</p> <p>2016-08-01</p> <p>Clinical risk-prediction <span class="hlt">models</span> serve an important role in healthcare. They are used for clinical decision-making and measuring the performance of healthcare providers. To establish confidence in a <span class="hlt">model</span>, external <span class="hlt">model</span> <span class="hlt">validation</span> is imperative. When designing such an external <span class="hlt">model</span> <span class="hlt">validation</span> study, thought must be given to patient selection, risk factor and outcome definitions, missing data, and the transparent reporting of the analysis. In addition, there are a number of statistical methods available for external <span class="hlt">model</span> <span class="hlt">validation</span>. Execution of a rigorous external <span class="hlt">validation</span> study rests in proper study design, application of suitable statistical methods, and transparent reporting. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1188881-epitaxial-fe-y2o3-interfaces-model-system-oxide-dispersion-strengthened-ferritic-alloys','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1188881-epitaxial-fe-y2o3-interfaces-model-system-oxide-dispersion-strengthened-ferritic-alloys"><span>Epitaxial <span class="hlt">Fe</span>/Y2O3 interfaces as a <span class="hlt">model</span> system for oxide-dispersion-strengthened ferritic alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kaspar, Tiffany C.; Bowden, Mark E.; Wang, Chong M.</p> <p>2015-02-01</p> <p>The fundamental mechanisms underlying the superior radiation tolerance properties of oxide-dispersion-strengthened ferritic steels and nanostructured ferritic alloys are poorly understood. Thin film heterostructures of <span class="hlt">Fe</span>/Y2O3 can serve as a <span class="hlt">model</span> system for fundamental studies of radiation damage. Epitaxial thin films of Y2O3 were deposited by pulsed laser deposition on 8% Y:ZrO2 (YSZ) substrates with (100), (110), and (111) orientation. Metallic <span class="hlt">Fe</span> was subsequently deposited by molecular beam epitaxy. Characterization by x-ray diffraction and Rutherford backscattering spectrometry in the channeling geometry revealed a degree of epitaxial or axiotaxial ntation for <span class="hlt">Fe</span>(211) deposited on Y2O3(110)/YSZ(110). In contrast, <span class="hlt">Fe</span> on Y2O3(111)/YSZ(111) was fullymore » polycrystalline, and <span class="hlt">Fe</span> on Y2O3(100)/YSZ(100) exhibited out-of-plane texture in the [110] direction with little or no preferential in-plane orientation. Scanning transmission electron microscopy imaging of <span class="hlt">Fe</span>(211)/Y2O3(110)/YSZ(110) revealed a strongly islanded morphology for the <span class="hlt">Fe</span> film, with no epitaxial grains visible in the cross-sectional sample. Well-ordered <span class="hlt">Fe</span> grains with no orientation to the underlying Y2O3 were observed. Well-ordered crystallites of <span class="hlt">Fe</span> with both epitaxial and non-epitaxial orientations on Y2O3 are a promising <span class="hlt">model</span> system for fundamental studies of radiation damage phenomena. This is illustrated with preliminary results of He bubble formation following implantation with a helium ion microscope. He bubble formation is shown to preferentially occur at the <span class="hlt">Fe</span>/Y2O3 interface.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA623514','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA623514"><span>Development of a Conservative <span class="hlt">Model</span> <span class="hlt">Validation</span> Approach for Reliable Analysis</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-01-01</p> <p>CIE 2015 August 2-5, 2015, Boston, Massachusetts, USA [DRAFT] DETC2015-46982 DEVELOPMENT OF A CONSERVATIVE <span class="hlt">MODEL</span> <span class="hlt">VALIDATION</span> APPROACH FOR RELIABLE...obtain a conservative simulation <span class="hlt">model</span> for reliable design even with limited experimental data. Very little research has taken into account the...3, the proposed conservative <span class="hlt">model</span> <span class="hlt">validation</span> is briefly compared to the conventional <span class="hlt">model</span> <span class="hlt">validation</span> approach. Section 4 describes how to account</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..MAR.L2009K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..MAR.L2009K"><span>Experiments, constitutive <span class="hlt">modeling</span> and <span class="hlt">FE</span> simulations of the impact behavior of Molybdenum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kleiser, Geremy; Revil-Baudard, Benoit</p> <p></p> <p>For polycrystalline high-purity molybdenum the feasibility of a Taylor test is questionable because the very large tensile stresses generated at impact would result in disintegration of the specimen. We report an experimental investigation and new <span class="hlt">model</span> to account simultaneously for the experimentally observed anisotropy, tension-compression asymmetry and strain-rate sensitivity of this material. To ensure high-fidelity predictions, a fully-implicit algorithm was used for implementing the new <span class="hlt">model</span> in the <span class="hlt">FE</span> code ABAQUS. Based on <span class="hlt">model</span> predictions, the impact velocity range was established for which specimens may be recovered. Taylor impact tests in this range (140-165 m/s) were successfully conducted for different specimen taken along the rolling direction (RD), the transverse direction and 45o to the RD. Comparison between the measured profiles of impact specimens and <span class="hlt">FE</span> <span class="hlt">model</span> predictions show excellent agreement. Furthermore, simulations were performed to gain understanding of the dynamic event: time evolution of the pressure, the extent of plastic deformation, distribution of plastic strain rates, and transition to quasi-stable deformation occurs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AAS...210.2513B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AAS...210.2513B"><span>Measurement And <span class="hlt">Modeling</span> Of <span class="hlt">Fe</span> VIII To <span class="hlt">Fe</span> XVI M-shell Emission In The Extreme Ultraviolet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beiersdorfer, Peter; Lepson, J. K.; Hurwitz, M.</p> <p>2007-05-01</p> <p>The solar EUV emission near 200 Å is presently being studied with high resolution with the Cosmic Hot Interstellar Plasma Spectrometer (CHIPS), which focuses on the emission between 90 and 270 Å, and with the EUV Imaging Spectrometer on Hinode, which focuses on the region 180 to 204 Å and 250 to 290 Å. The Solar EUV Experiment on the TIMED spacecraft also observes this spectral band but with greatly reduced resolution. The spectrum in this region is dominated by emission from moderate charge states of iron. The interpretation of the data relies on accurate and complete plasma emission <span class="hlt">models</span>, notably CHIANTI. We have performed a series of laboratory measurements of the 3-3 emission from M-shell iron ions. The measurements cover the range 170 - 250 Å and are made at an electron density of about 1011 cm-3. Emission from <span class="hlt">Fe</span> VIII through <span class="hlt">Fe</span> XVI has been identified. Excellent agreement with CHIANTI predictions is found. A few weak transitions are noted in the laboratory data that are predicted by CHIANTI to be vanishingly small and should not have been observed. These are tentatively attributed to transitions in <span class="hlt">Fe</span> XV. A comparison with observations from CHIPS is also presented. This work was supported in part by NASA's Solar and Heliospheric Physics Supporting Research and Technology Program. Work at UC-LLNL was performed under the auspices of the DOE by under Contract W-7405-Eng-48.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3644562','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3644562"><span>NRVS and EPR Spectroscopy of 57<span class="hlt">Fe</span>-enriched [<span class="hlt">FeFe</span>] Hydrogenase Indicate Stepwise Assembly of the H-cluster†</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kuchenreuther, Jon M.; Guo, Yisong; Wang, Hongxin; Myers, William K.; George, Simon J.; Boyke, Christine A.; Yoda, Yoshitaka; Alp, E. Ercan; Zhao, Jiyong; Britt, R. David; Swartz, James R.; Cramer, Stephen P.</p> <p>2013-01-01</p> <p>The [<span class="hlt">FeFe</span>] hydrogenase from Clostridium pasteurianum (CpI) harbors four Fe–S clusters that facilitate electron transfer to the H-cluster, a ligand-coordinated six-iron prosthetic group that catalyzes the redox interconversion of protons and H2. Here, we have used 57<span class="hlt">Fe</span> nuclear resonance vibrational spectroscopy (NRVS) to study the iron centers in CpI, and we compare our data to that for a [4Fe–4S] ferredoxin as well as a <span class="hlt">model</span> complex resembling the [2<span class="hlt">Fe</span>]H catalytic domain of the H-cluster. In order to enrich the hydrogenase with 57<span class="hlt">Fe</span> nuclei, we used cell-free methods to post-translationally mature the enzyme. Specifically, inactive CpI apoprotein with 56<span class="hlt">Fe</span>-labeled Fe–S clusters was activated in vitro using 57<span class="hlt">Fe</span>-enriched maturation proteins. This approach enabled us to selectively label the [2<span class="hlt">Fe</span>]H subcluster with 57<span class="hlt">Fe</span>, which NRVS confirms by detecting 57Fe–CO and 57Fe–CN normal modes from the H-cluster nonprotein ligands. The NRVS and iron quantification results also suggest that the hydrogenase contains a second 57Fe–S cluster. EPR spectroscopy indicates that this 57<span class="hlt">Fe</span>-enriched metal center is not the [4Fe– 4S]H subcluster of the H-cluster. This finding demonstrates that the CpI hydrogenase retained an 56<span class="hlt">Fe</span>-enriched [4Fe–4S]H cluster during in vitro maturation, providing unambiguous evidence for stepwise assembly of the H-cluster. In addition, this work represents the first NRVS characterization of [<span class="hlt">FeFe</span>] hydrogenases. PMID:23249091</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.6995S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.6995S"><span>Feasibility of diffuse reflectance infrared Fourier spectroscopy (DRIFTS) to quantify iron-cyanide (<span class="hlt">Fe</span>-CN) complexes in soil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sut-Lohmann, Magdalena; Raab, Thomas</p> <p>2017-04-01</p> <p>Contaminated sites create a significant risk to human health, by poisoning drinking water, soil, air and as a consequence food. Continuous release of persistent iron-cyanide (<span class="hlt">Fe</span>-CN) complexes from various industrial sources poses a high hazard to the environment and indicates the necessity to analyze considerable amount of samples. At the present time quantitative determination of <span class="hlt">Fe</span>-CN concentration in soil usually requires a time consuming two step process: digestion of the sample (e.g., micro distillation system) and its analytical detection performed, e.g., by automated spectrophotometrical flow injection analysis (FIA). In order to determine the feasibility of diffuse reflectance infrared Fourier spectroscopy (DRIFTS) to quantify the <span class="hlt">Fe</span>-CN complexes in soil matrix, 42 soil samples were collected (8 to 12.520 mg kg-1CN) indicating single symmetrical CN band in the range 2092 - 2084 cm-1. Partial least squares (PLS) calibration-<span class="hlt">validation</span> <span class="hlt">model</span> revealed IR response to CNtot exceeding 1268 mg kg-1 (limit of detection, LOD). Subsequently, leave-one-out cross-<span class="hlt">validation</span> (LOO-CV) was performed on soil samples containing low CNtot (<900 mg kg-1), which improved the sensitivity of the <span class="hlt">model</span> by reducing the LOD to 154 mg kg-1. Finally, the LOO-CV conducted on the samples with CNtot >900 mg kg-1 resulted in LOD equal to 3494 mg kg-1. Our results indicate that spectroscopic data in combination with PLS statistics can efficiently be used to predict <span class="hlt">Fe</span>-CN concentrations in soil. We conclude that the protocol applied in this study can strongly reduce the time and costs essential for the spatial and vertical screening of the site affected by complexed <span class="hlt">Fe</span>-CN.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JHyd..482..119H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JHyd..482..119H"><span>Applicability of Monte Carlo cross <span class="hlt">validation</span> technique for <span class="hlt">model</span> development and <span class="hlt">validation</span> using generalised least squares regression</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haddad, Khaled; Rahman, Ataur; A Zaman, Mohammad; Shrestha, Surendra</p> <p>2013-03-01</p> <p>SummaryIn regional hydrologic regression analysis, <span class="hlt">model</span> selection and <span class="hlt">validation</span> are regarded as important steps. Here, the <span class="hlt">model</span> selection is usually based on some measurements of goodness-of-fit between the <span class="hlt">model</span> prediction and observed data. In Regional Flood Frequency Analysis (RFFA), leave-one-out (LOO) <span class="hlt">validation</span> or a fixed percentage leave out <span class="hlt">validation</span> (e.g., 10%) is commonly adopted to assess the predictive ability of regression-based prediction equations. This paper develops a Monte Carlo Cross <span class="hlt">Validation</span> (MCCV) technique (which has widely been adopted in Chemometrics and Econometrics) in RFFA using Generalised Least Squares Regression (GLSR) and compares it with the most commonly adopted LOO <span class="hlt">validation</span> approach. The study uses simulated and regional flood data from the state of New South Wales in Australia. It is found that when developing hydrologic regression <span class="hlt">models</span>, application of the MCCV is likely to result in a more parsimonious <span class="hlt">model</span> than the LOO. It has also been found that the MCCV can provide a more realistic estimate of a <span class="hlt">model</span>'s predictive ability when compared with the LOO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ccr.cancer.gov/node/2832','NCI'); return false;" href="https://ccr.cancer.gov/node/2832"><span><span class="hlt">Model</span> <span class="hlt">Validation</span> | Center for Cancer Research</span></a></p> <p><a target="_blank" href="http://www.cancer.gov">Cancer.gov</a></p> <p></p> <p></p> <p>Research Investigation and Animal <span class="hlt">Model</span> <span class="hlt">Validation</span> This activity is also under development and thus far has included increasing pathology resources, delivering pathology services, as well as using imaging and surgical methods to develop and refine animal <span class="hlt">models</span> in collaboration with other CCR investigators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991PhDT........39K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991PhDT........39K"><span>Quantitative <span class="hlt">model</span> <span class="hlt">validation</span> of manipulative robot systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kartowisastro, Iman Herwidiana</p> <p></p> <p>This thesis is concerned with applying the distortion quantitative <span class="hlt">validation</span> technique to a robot manipulative system with revolute joints. Using the distortion technique to <span class="hlt">validate</span> a <span class="hlt">model</span> quantitatively, the <span class="hlt">model</span> parameter uncertainties are taken into account in assessing the faithfulness of the <span class="hlt">model</span> and this approach is relatively more objective than the commonly visual comparison method. The industrial robot is represented by the TQ MA2000 robot arm. Details of the mathematical derivation of the distortion technique are given which explains the required distortion of the constant parameters within the <span class="hlt">model</span> and the assessment of <span class="hlt">model</span> adequacy. Due to the complexity of a robot <span class="hlt">model</span>, only the first three degrees of freedom are considered where all links are assumed rigid. The <span class="hlt">modelling</span> involves the Newton-Euler approach to obtain the dynamics <span class="hlt">model</span>, and the Denavit-Hartenberg convention is used throughout the work. The conventional feedback control system is used in developing the <span class="hlt">model</span>. The system behavior to parameter changes is investigated as some parameters are redundant. This work is important so that the most important parameters to be distorted can be selected and this leads to a new term called the fundamental parameters. The transfer function approach has been chosen to <span class="hlt">validate</span> an industrial robot quantitatively against the measured data due to its practicality. Initially, the assessment of the <span class="hlt">model</span> fidelity criterion indicated that the <span class="hlt">model</span> was not capable of explaining the transient record in term of the <span class="hlt">model</span> parameter uncertainties. Further investigations led to significant improvements of the <span class="hlt">model</span> and better understanding of the <span class="hlt">model</span> properties. After several improvements in the <span class="hlt">model</span>, the fidelity criterion obtained was almost satisfied. Although the fidelity criterion is slightly less than unity, it has been shown that the distortion technique can be applied in a robot manipulative system. Using the <span class="hlt">validated</span> <span class="hlt">model</span>, the importance of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1239147-economic-analysis-model-validation-challenge-problem','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1239147-economic-analysis-model-validation-challenge-problem"><span>Economic analysis of <span class="hlt">model</span> <span class="hlt">validation</span> for a challenge problem</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Paez, Paul J.; Paez, Thomas L.; Hasselman, Timothy K.</p> <p>2016-02-19</p> <p>It is now commonplace for engineers to build mathematical <span class="hlt">models</span> of the systems they are designing, building, or testing. And, it is nearly universally accepted that phenomenological <span class="hlt">models</span> of physical systems must be <span class="hlt">validated</span> prior to use for prediction in consequential scenarios. Yet, there are certain situations in which testing only or no testing and no <span class="hlt">modeling</span> may be economically viable alternatives to <span class="hlt">modeling</span> and its associated testing. This paper develops an economic framework within which benefit–cost can be evaluated for <span class="hlt">modeling</span> and <span class="hlt">model</span> <span class="hlt">validation</span> relative to other options. The development is presented in terms of a challenge problem. Asmore » a result, we provide a numerical example that quantifies when <span class="hlt">modeling</span>, calibration, and <span class="hlt">validation</span> yield higher benefit–cost than a testing only or no <span class="hlt">modeling</span> and no testing option.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150008713&hterms=Shaun&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DShaun%2BM','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150008713&hterms=Shaun&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DShaun%2BM"><span><span class="hlt">Model</span>-Based Verification and <span class="hlt">Validation</span> of Spacecraft Avionics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Khan, M. Omair; Sievers, Michael; Standley, Shaun</p> <p>2012-01-01</p> <p>Verification and <span class="hlt">Validation</span> (V&V) at JPL is traditionally performed on flight or flight-like hardware running flight software. For some time, the complexity of avionics has increased exponentially while the time allocated for system integration and associated V&V testing has remained fixed. There is an increasing need to perform comprehensive system level V&V using <span class="hlt">modeling</span> and simulation, and to use scarce hardware testing time to <span class="hlt">validate</span> <span class="hlt">models</span>; the norm for thermal and structural V&V for some time. Our approach extends <span class="hlt">model</span>-based V&V to electronics and software through functional and structural <span class="hlt">models</span> implemented in SysML. We develop component <span class="hlt">models</span> of electronics and software that are <span class="hlt">validated</span> by comparison with test results from actual equipment. The <span class="hlt">models</span> are then simulated enabling a more complete set of test cases than possible on flight hardware. SysML simulations provide access and control of internal nodes that may not be available in physical systems. This is particularly helpful in testing fault protection behaviors when injecting faults is either not possible or potentially damaging to the hardware. We can also <span class="hlt">model</span> both hardware and software behaviors in SysML, which allows us to simulate hardware and software interactions. With an integrated <span class="hlt">model</span> and simulation capability we can evaluate the hardware and software interactions and identify problems sooner. The primary missing piece is <span class="hlt">validating</span> SysML <span class="hlt">model</span> correctness against hardware; this experiment demonstrated such an approach is possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MSSP..102..401C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MSSP..102..401C"><span>Integration of system identification and finite element <span class="hlt">modelling</span> of nonlinear vibrating structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cooper, Samson B.; DiMaio, Dario; Ewins, David J.</p> <p>2018-03-01</p> <p>The Finite Element Method (FEM), Experimental modal analysis (EMA) and other linear analysis techniques have been established as reliable tools for the dynamic analysis of engineering structures. They are often used to provide solutions to small and large structures and other variety of cases in structural dynamics, even those exhibiting a certain degree of nonlinearity. Unfortunately, when the nonlinear effects are substantial or the accuracy of the predicted response is of vital importance, a linear finite element <span class="hlt">model</span> will generally prove to be unsatisfactory. As a result, the <span class="hlt">validated</span> linear <span class="hlt">FE</span> <span class="hlt">model</span> requires further enhancement so that it can represent and predict the nonlinear behaviour exhibited by the structure. In this paper, a pragmatic approach to integrating test-based system identification and <span class="hlt">FE</span> <span class="hlt">modelling</span> of a nonlinear structure is presented. This integration is based on three different phases: the first phase involves the derivation of an Underlying Linear <span class="hlt">Model</span> (ULM) of the structure, the second phase includes experiment-based nonlinear identification using measured time series and the third phase covers augmenting the linear <span class="hlt">FE</span> <span class="hlt">model</span> and experimental <span class="hlt">validation</span> of the nonlinear <span class="hlt">FE</span> <span class="hlt">model</span>. The proposed case study is demonstrated on a twin cantilever beam assembly coupled with a flexible arch shaped beam. In this case, polynomial-type nonlinearities are identified and <span class="hlt">validated</span> with force-controlled stepped-sine test data at several excitation levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16633666','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16633666"><span>A kinetic study of the reactions <span class="hlt">Fe</span>O+ + O, <span class="hlt">Fe</span>+.N2 + O, <span class="hlt">Fe</span>+.O2 + O and <span class="hlt">Fe</span>O+ + CO: implications for sporadic E layers in the upper atmosphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Woodcock, K R S; Vondrak, T; Meech, S R; Plane, J M C</p> <p>2006-04-21</p> <p>These gas-phase reactions were studied by pulsed laser ablation of an iron target to produce <span class="hlt">Fe</span>(+) in a fast flow tube, with detection of the ions by quadrupole mass spectrometry. <span class="hlt">Fe</span>(+).N(2) and <span class="hlt">Fe</span>(+).O(2) were produced by injecting N(2) and O(2), respectively, into the flow tube. <span class="hlt">Fe</span>O(+) was produced from <span class="hlt">Fe</span>(+) by addition of N(2)O, or by ligand-switching from <span class="hlt">Fe</span>(+).N(2) following the addition of atomic O. The following rate coefficients were measured: k(<span class="hlt">Fe</span>O(+) + O --> <span class="hlt">Fe</span>(+) + O(2), 186-294 K) = (3.2 +/- 1.5) x 10(-11); k(<span class="hlt">Fe</span>(+).N(2) + O --> <span class="hlt">Fe</span>O(+)+ N(2), 294 K) = (4.6 +/- 2.5) x 10(-10); k(<span class="hlt">Fe</span>(+).O(2) + O --> <span class="hlt">Fe</span>O(+) + O(2), 294 K) = (6.3 +/- 2.7) x 10(-11); and k(<span class="hlt">Fe</span>O(+) + CO --> <span class="hlt">Fe</span>(+) + CO(2), 294 K) = (1.59 +/- 0.34) x 10(-10) cm(3) molecule(-1) s(-1), where the quoted uncertainties are a combination of the 1sigma standard errors in the kinetic data and the systematic experimental errors. The surprisingly slow reaction between <span class="hlt">Fe</span>O(+) and O is examined using ab initio quantum calculations of the relevant potential energy surfaces. The importance of this reaction for controlling the lifetime of sporadic E layers is then demonstrated using a <span class="hlt">model</span> of the upper mesosphere and lower thermosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1340645-identification-catalytic-iron-hydride-cluster-fefe-hydrogenase','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1340645-identification-catalytic-iron-hydride-cluster-fefe-hydrogenase"><span>Identification of a catalytic iron-hydride at the H-cluster of [<span class="hlt">FeFe</span>]-hydrogenase</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Mulder, David W.; Guo, Yisong; Ratzloff, Michael W.; ...</p> <p>2016-12-14</p> <p>Hydrogenases couple electrochemical potential to the reversible chemical transformation of H 2 and protons, yet the reaction mechanism and composition of intermediates are not fully understood. In this Communication we describe the biophysical properties of a hydride-bound state (H hyd) of the [<span class="hlt">FeFe</span>]-hydrogenase from Chlamydomonas reinhardtii. The catalytic H-cluster of [<span class="hlt">FeFe</span>]-hydrogenase consists of a [4<span class="hlt">Fe</span>-4S] subcluster ([4<span class="hlt">Fe</span>-4S] H) linked by a cysteine thiol to an azadithiolate-bridged 2<span class="hlt">Fe</span> subcluster ([2<span class="hlt">Fe</span>] H) with CO and CN- ligands. Mossbauer analysis and density functional theory (DFT) calculations show that H hyd consists of a reduced [4<span class="hlt">Fe</span>-4S] H + coupled to a diferrous [2<span class="hlt">Fe</span>] Hmore » with a terminally bound <span class="hlt">Fe</span>-hydride. The existence of the <span class="hlt">Fe</span>-hydride in Hhyd was demonstrated by an unusually low Mossbauer isomer shift of the distal <span class="hlt">Fe</span> of the [2<span class="hlt">Fe</span>] H subcluster. As a result, a DFT <span class="hlt">model</span> of H hyd shows that the <span class="hlt">Fe</span>-hydride is part of a H-bonding network with the nearby bridging azadithiolate to facilitate fast proton exchange and catalytic turnover.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1261062','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1261062"><span>NEAMS-ATF M3 Milestone Report: Literature Review of <span class="hlt">Modeling</span> of Radiation-Induced Swelling in <span class="hlt">Fe</span>-Cr-Al Steels</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bai, Xianming; Biner, Suleyman Bulent; Jiang, Chao</p> <p>2015-12-01</p> <p><span class="hlt">Fe</span>-Cr-Al steels are proposed as accident-tolerant-fuel (ATF) cladding materials in light water reactors due to their excellent oxidation resistance at high temperatures. Currently, the understanding of their performance in reactor environment is still limited. In this review, firstly we reviewed the experimental studies of <span class="hlt">Fe</span>-Cr-Al based alloys with particular focus on the radiation effects in these alloys. Although limited data are available in literature, several previous and recent experimental studies have shown that <span class="hlt">Fe</span>-Cr-Al based alloys have very good void swelling resistance at low and moderate irradiation doses but the growth of dislocation loops is very active. Overall, the behaviormore » of radiation damage evolution is similar to that in <span class="hlt">Fe</span>-Cr ferritic/martensitic alloys. Secondly, we reviewed the rate theory-based <span class="hlt">modeling</span> methods for <span class="hlt">modeling</span> the coevolution of voids and dislocation loops in materials under irradiation such as Frenkel pair three-dimensional diffusion <span class="hlt">model</span> (FP3DM) and cluster dynamics. Finally, we summarized and discussed our review and proposed our future plans for <span class="hlt">modeling</span> radiation damage in <span class="hlt">Fe</span>-Cr-Al based alloys.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95f4415O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95f4415O"><span><span class="hlt">Modeling</span> the thickness dependence of the magnetic phase transition temperature in thin <span class="hlt">Fe</span>Rh films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ostler, Thomas Andrew; Barton, Craig; Thomson, Thomas; Hrkac, Gino</p> <p>2017-02-01</p> <p><span class="hlt">Fe</span>Rh and its first-order phase transition can open new routes for magnetic hybrid materials and devices under the assumption that it can be exploited in ultra-thin-film structures. Motivated by experimental measurements showing an unexpected increase in the phase transition temperature with decreasing thickness of <span class="hlt">Fe</span>Rh on top of MgO, we develop a computational <span class="hlt">model</span> to investigate strain effects of <span class="hlt">Fe</span>Rh in such magnetic structures. Our theoretical results show that the presence of the MgO interface results in a strain that changes the magnetic configuration which drives the anomalous behavior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950013224','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950013224"><span>Real-time remote scientific <span class="hlt">model</span> <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Frainier, Richard; Groleau, Nicolas</p> <p>1994-01-01</p> <p>This paper describes flight results from the use of a CLIPS-based <span class="hlt">validation</span> facility to compare analyzed data from a space life sciences (SLS) experiment to an investigator's preflight <span class="hlt">model</span>. The comparison, performed in real-time, either confirms or refutes the <span class="hlt">model</span> and its predictions. This result then becomes the basis for continuing or modifying the investigator's experiment protocol. Typically, neither the astronaut crew in Spacelab nor the ground-based investigator team are able to react to their experiment data in real time. This facility, part of a larger science advisor system called Principal Investigator in a Box, was flown on the space shuttle in October, 1993. The software system aided the conduct of a human vestibular physiology experiment and was able to outperform humans in the tasks of data integrity assurance, data analysis, and scientific <span class="hlt">model</span> <span class="hlt">validation</span>. Of twelve preflight hypotheses associated with investigator's <span class="hlt">model</span>, seven were confirmed and five were rejected or compromised.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2941217','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2941217"><span><span class="hlt">Validation</span> of Computational <span class="hlt">Models</span> in Biomechanics</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Henninger, Heath B.; Reese, Shawn P.; Anderson, Andrew E.; Weiss, Jeffrey A.</p> <p>2010-01-01</p> <p>The topics of verification and <span class="hlt">validation</span> (V&V) have increasingly been discussed in the field of computational biomechanics, and many recent articles have applied these concepts in an attempt to build credibility for <span class="hlt">models</span> of complex biological systems. V&V are evolving techniques that, if used improperly, can lead to false conclusions about a system under study. In basic science these erroneous conclusions may lead to failure of a subsequent hypothesis, but they can have more profound effects if the <span class="hlt">model</span> is designed to predict patient outcomes. While several authors have reviewed V&V as they pertain to traditional solid and fluid mechanics, it is the intent of this manuscript to present them in the context of computational biomechanics. Specifically, the task of <span class="hlt">model</span> <span class="hlt">validation</span> will be discussed with a focus on current techniques. It is hoped that this review will encourage investigators to engage and adopt the V&V process in an effort to increase peer acceptance of computational biomechanics <span class="hlt">models</span>. PMID:20839648</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP51C1142B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP51C1142B"><span><span class="hlt">Fe</span> Isotope Fractionation During <span class="hlt">Fe</span>(III) Reduction to <span class="hlt">Fe</span>(II)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baker, E. A.; Greene, S.; Hardin, E. E.; Hodierne, C. E.; Rosenberg, A.; John, S.</p> <p>2014-12-01</p> <p>The redox chemistry of <span class="hlt">Fe</span>(III) and <span class="hlt">Fe</span>(II) is tied to a variety of earth processes, including biological, chemical, or photochemical reduction of <span class="hlt">Fe</span>(III) to <span class="hlt">Fe</span>(II). Each process may fractionate <span class="hlt">Fe</span> isotopes, but the magnitudes of the kinetic isotope effects have not been greatly explored in laboratory conditions. Here, we present the isotopic fractionation of <span class="hlt">Fe</span> during reduction experiments under a variety of experimental conditions including photochemical reduction of <span class="hlt">Fe</span>(III) bound to EDTA or glucaric acid, and chemical reduction of <span class="hlt">Fe</span>-EDTA by sodium dithionite, hydroxylamine hydrochloride, Mn(II), and ascorbic acid. A variety of temperatures and pHs were tested. In all experiments, <span class="hlt">Fe</span>(III) bound to an organic ligand was reduced in the presence of ferrozine. Ferrozine binds with <span class="hlt">Fe</span>(II), forming a purple complex which allows us to measure the extent of reaction. The absorbance of the experimental solutions was measured over time to determine the <span class="hlt">Fe</span>(II)-ferrozine concentration and thus the reduction rate. After about 5% of the <span class="hlt">Fe</span>(III) was reduced, <span class="hlt">Fe</span>(III)-EDTA and <span class="hlt">Fe</span>(II)-ferrozine were separated using a C-18 column to which <span class="hlt">Fe</span>(II)-ferrozine binds. The <span class="hlt">Fe</span>(II) was eluted and purified through anion exchange chromatography for analysis of δ56<span class="hlt">Fe</span> by MC-ICPMS. Preliminary results show that temperature and pH both affect reduction rate. All chemical reductants tested reduce <span class="hlt">Fe</span>(III) at a greater rate as temperature increases. The photochemical reductant EDTA reduces <span class="hlt">Fe</span>(III) at a greater rate under more acidic conditions. Comparison of the two photochemical reductants shows that glucaric acid reduces <span class="hlt">Fe</span>(III) significantly faster than EDTA. For chemical reduction, the magnitude of isotopic fractionation depends on the reductant used. Temperature and pH also affect the isotopic fractionation of <span class="hlt">Fe</span>. Experiments using chemical reductants show that an increase in temperature at low temperatures produces lighter 56<span class="hlt">Fe</span> ratios, while at high temperatures some reductants produce heavier</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110008735','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110008735"><span><span class="hlt">Validation</span> of <span class="hlt">Model</span> Forecasts of the Ambient Solar Wind</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Macneice, P. J.; Hesse, M.; Kuznetsova, M. M.; Rastaetter, L.; Taktakishvili, A.</p> <p>2009-01-01</p> <p>Independent and automated <span class="hlt">validation</span> is a vital step in the progression of <span class="hlt">models</span> from the research community into operational forecasting use. In this paper we describe a program in development at the CCMC to provide just such a comprehensive <span class="hlt">validation</span> for <span class="hlt">models</span> of the ambient solar wind in the inner heliosphere. We have built upon previous efforts published in the community, sharpened their definitions, and completed a baseline study. We also provide first results from this program of the comparative performance of the MHD <span class="hlt">models</span> available at the CCMC against that of the Wang-Sheeley-Arge (WSA) <span class="hlt">model</span>. An important goal of this effort is to provide a consistent <span class="hlt">validation</span> to all available <span class="hlt">models</span>. Clearly exposing the relative strengths and weaknesses of the different <span class="hlt">models</span> will enable forecasters to craft more reliable ensemble forecasting strategies. <span class="hlt">Models</span> of the ambient solar wind are developing rapidly as a result of improvements in data supply, numerical techniques, and computing resources. It is anticipated that in the next five to ten years, the MHD based <span class="hlt">models</span> will supplant semi-empirical potential based <span class="hlt">models</span> such as the WSA <span class="hlt">model</span>, as the best available forecast <span class="hlt">models</span>. We anticipate that this <span class="hlt">validation</span> effort will track this evolution and so assist policy makers in gauging the value of past and future investment in <span class="hlt">modeling</span> support.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20414728','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20414728"><span>3D micro-crack propagation simulation at enamel/adhesive interface using <span class="hlt">FE</span> submodeling and element death techniques.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Heng-Liang; Lin, Chun-Li; Sun, Ming-Tsung; Chang, Yen-Hsiang</p> <p>2010-06-01</p> <p>This study investigates micro-crack propagation at the enamel/adhesive interface using finite element (<span class="hlt">FE</span>) submodeling and element death techniques. A three-dimensional (3D) <span class="hlt">FE</span> macro-<span class="hlt">model</span> of the enamel/adhesive/ceramic subjected to shear bond testing was generated and analyzed. A 3D micro-<span class="hlt">model</span> with interfacial bonding structure was constructed at the upper enamel/adhesive interface where the stress concentration was found from the macro-<span class="hlt">model</span> results. The morphology of this interfacial bonding structure (i.e., resin tag) was assigned based on resin tag geometry and enamel rod arrangement from a scanning electron microscopy micrograph. The boundary conditions for the micro-<span class="hlt">model</span> were determined from the macro-<span class="hlt">model</span> results. A custom iterative code combined with the element death technique was used to calculate the micro-crack propagation. Parallel experiments were performed to <span class="hlt">validate</span> this <span class="hlt">FE</span> simulation. The stress concentration within the adhesive occurred mainly at the upper corner near the enamel/adhesive interface and the resin tag base. A simulated fracture path was found at the resin tag base along the enamel/adhesive interface. A morphological observation of the fracture patterns obtained from in vitro testing corresponded with the simulation results. This study shows that the <span class="hlt">FE</span> submodeling and element death techniques could be used to simulate the 3D micro-stress pattern and the crack propagation noted at the enamel/adhesive interface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2011/5025/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2011/5025/"><span>Three-dimensional geologic <span class="hlt">model</span> of the southeastern Espanola Basin, Santa <span class="hlt">Fe</span> County, New Mexico</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pantea, Michael P.; Hudson, Mark R.; Grauch, V.J.S.; Minor, Scott A.</p> <p>2011-01-01</p> <p>This multimedia <span class="hlt">model</span> and report show and describe digital three-dimensional faulted surfaces and volumes of lithologic units that confine and constrain the basin-fill aquifers within the Espanola Basin of north-central New Mexico. These aquifers are the primary groundwater resource for the cities of Santa <span class="hlt">Fe</span> and Espanola, six Pueblo nations, and the surrounding areas. The <span class="hlt">model</span> presented in this report is a synthesis of geologic information that includes (1) aeromagnetic and gravity data and seismic cross sections; (2) lithologic descriptions, interpretations, and geophysical logs from selected drill holes; (3) geologic maps, geologic cross sections, and interpretations; and (4) mapped faults and interpreted faults from geophysical data. <span class="hlt">Modeled</span> faults individually or collectively affect the continuity of the rocks that contain the basin aquifers; they also help define the form of this rift basin. Structure, trend, and dip data not previously published were added; these structures are derived from interpretations of geophysical information and recent field observations. Where possible, data were compared and <span class="hlt">validated</span> and reflect the complex relations of structures in this part of the Rio Grande rift. This interactive geologic framework <span class="hlt">model</span> can be used as a tool to visually explore and study geologic structures within the Espanola Basin, to show the connectivity of geologic units of high and low permeability between and across faults, and to show approximate dips of the lithologic units. The viewing software can be used to display other data and information, such as drill-hole data, within this geologic framework <span class="hlt">model</span> in three-dimensional space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28639302','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28639302"><span>Prospective <span class="hlt">validation</span> of pathologic complete response <span class="hlt">models</span> in rectal cancer: Transferability and reproducibility.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Soest, Johan; Meldolesi, Elisa; van Stiphout, Ruud; Gatta, Roberto; Damiani, Andrea; Valentini, Vincenzo; Lambin, Philippe; Dekker, Andre</p> <p>2017-09-01</p> <p>Multiple <span class="hlt">models</span> have been developed to predict pathologic complete response (pCR) in locally advanced rectal cancer patients. Unfortunately, <span class="hlt">validation</span> of these <span class="hlt">models</span> normally omit the implications of cohort differences on prediction <span class="hlt">model</span> performance. In this work, we will perform a prospective <span class="hlt">validation</span> of three pCR <span class="hlt">models</span>, including information whether this <span class="hlt">validation</span> will target transferability or reproducibility (cohort differences) of the given <span class="hlt">models</span>. We applied a novel methodology, the cohort differences <span class="hlt">model</span>, to predict whether a patient belongs to the training or to the <span class="hlt">validation</span> cohort. If the cohort differences <span class="hlt">model</span> performs well, it would suggest a large difference in cohort characteristics meaning we would <span class="hlt">validate</span> the transferability of the <span class="hlt">model</span> rather than reproducibility. We tested our method in a prospective <span class="hlt">validation</span> of three existing <span class="hlt">models</span> for pCR prediction in 154 patients. Our results showed a large difference between training and <span class="hlt">validation</span> cohort for one of the three tested <span class="hlt">models</span> [Area under the Receiver Operating Curve (AUC) cohort differences <span class="hlt">model</span>: 0.85], signaling the <span class="hlt">validation</span> leans towards transferability. Two out of three <span class="hlt">models</span> had a lower AUC for <span class="hlt">validation</span> (0.66 and 0.58), one <span class="hlt">model</span> showed a higher AUC in the <span class="hlt">validation</span> cohort (0.70). We have successfully applied a new methodology in the <span class="hlt">validation</span> of three prediction <span class="hlt">models</span>, which allows us to indicate if a <span class="hlt">validation</span> targeted transferability (large differences between training/<span class="hlt">validation</span> cohort) or reproducibility (small cohort differences). © 2017 American Association of Physicists in Medicine.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JMMM..430...78H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMMM..430...78H"><span>Kerr microscopy study of exchange-coupled <span class="hlt">FePt/Fe</span> exchange spring magnets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hussain, Zaineb; Kumar, Dileep; Reddy, V. Raghavendra; Gupta, Ajay</p> <p>2017-05-01</p> <p>Magnetization reversal and magnetic microstructure of top soft magnetic layer (<span class="hlt">Fe</span>) in exchange spring coupled L10 <span class="hlt">FePt/Fe</span> is studied using high resolution Kerr microscopy. With remnant state of the hard magnetic layer (L10 <span class="hlt">Fe</span>Pt) as initial condition, magnetization loops along with magnetic domains are recorded for the top soft magnetic layer (<span class="hlt">Fe</span>) using Kerr microscopy. Considerable shifting of <span class="hlt">Fe</span> layer hysteresis loop from center which is similar to exchange bias phenomena is observed. It is also observed that one can tune the magnitude of hysteresis shift by reaching the remanent state from different saturating fields (HSAT) and also by varying the angle between measuring field and HSAT. The hysteresis loops and magnetic domains of top soft <span class="hlt">Fe</span> layer demonstrate unambiguously that soft magnetic layer at remanent state in such exchange coupled system is having unidirectional anisotropy. An analogy is drawn and the observations are explained in terms of established <span class="hlt">model</span> of exchange bias phenomena framed for field-cooled ferromagnetic - antiferromagnetic bilayer systems.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4534600','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4534600"><span>Heavy Metal Adsorption onto Kappaphycus sp. from Aqueous Solutions: The Use of Error Functions for <span class="hlt">Validation</span> of Isotherm and Kinetics <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rahman, Md. Sayedur; Sathasivam, Kathiresan V.</p> <p>2015-01-01</p> <p>Biosorption process is a promising technology for the removal of heavy metals from industrial wastes and effluents using low-cost and effective biosorbents. In the present study, adsorption of Pb2+, Cu2+, <span class="hlt">Fe</span>2+, and Zn2+ onto dried biomass of red seaweed Kappaphycus sp. was investigated as a function of pH, contact time, initial metal ion concentration, and temperature. The experimental data were evaluated by four isotherm <span class="hlt">models</span> (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich) and four kinetic <span class="hlt">models</span> (pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion <span class="hlt">models</span>). The adsorption process was feasible, spontaneous, and endothermic in nature. Functional groups in the biomass involved in metal adsorption process were revealed as carboxylic and sulfonic acids and sulfonate by Fourier transform infrared analysis. A total of nine error functions were applied to <span class="hlt">validate</span> the <span class="hlt">models</span>. We strongly suggest the analysis of error functions for <span class="hlt">validating</span> adsorption isotherm and kinetic <span class="hlt">models</span> using linear methods. The present work shows that the red seaweed Kappaphycus sp. can be used as a potentially low-cost biosorbent for the removal of heavy metal ions from aqueous solutions. Further study is warranted to evaluate its feasibility for the removal of heavy metals from the real environment. PMID:26295032</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26295032','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26295032"><span>Heavy Metal Adsorption onto Kappaphycus sp. from Aqueous Solutions: The Use of Error Functions for <span class="hlt">Validation</span> of Isotherm and Kinetics <span class="hlt">Models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rahman, Md Sayedur; Sathasivam, Kathiresan V</p> <p>2015-01-01</p> <p>Biosorption process is a promising technology for the removal of heavy metals from industrial wastes and effluents using low-cost and effective biosorbents. In the present study, adsorption of Pb(2+), Cu(2+), <span class="hlt">Fe</span>(2+), and Zn(2+) onto dried biomass of red seaweed Kappaphycus sp. was investigated as a function of pH, contact time, initial metal ion concentration, and temperature. The experimental data were evaluated by four isotherm <span class="hlt">models</span> (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich) and four kinetic <span class="hlt">models</span> (pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion <span class="hlt">models</span>). The adsorption process was feasible, spontaneous, and endothermic in nature. Functional groups in the biomass involved in metal adsorption process were revealed as carboxylic and sulfonic acids and sulfonate by Fourier transform infrared analysis. A total of nine error functions were applied to <span class="hlt">validate</span> the <span class="hlt">models</span>. We strongly suggest the analysis of error functions for <span class="hlt">validating</span> adsorption isotherm and kinetic <span class="hlt">models</span> using linear methods. The present work shows that the red seaweed Kappaphycus sp. can be used as a potentially low-cost biosorbent for the removal of heavy metal ions from aqueous solutions. Further study is warranted to evaluate its feasibility for the removal of heavy metals from the real environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1317917','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1317917"><span>Modulation of the electronic structure and the Ni–<span class="hlt">Fe</span> distance in heterobimetallic <span class="hlt">models</span> for the active site in [Ni<span class="hlt">Fe</span>]hydrogenase</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhu, Wenfeng; Marr, Andrew C.; Wang, Qiang; Neese, Frank; Spencer, Douglas J. E.; Blake, Alexander J.; Cooke, Paul A.; Wilson, Claire; Schröder, Martin</p> <p>2005-01-01</p> <p>Reaction of the mononuclear Ni(II) thiolate complexes [Ni(L)] [L, L1, H2L1, bis(2-mercaptoethyl)-1,2-dimercaptoethane; L2, H2L2, N,N′-dimethyl-N,N′-bis(2-mercaptoethyl)-bis(aminoethyl)sulfide] with [<span class="hlt">Fe</span>Cp(CO)2I] gives the dithiolate-bridged heterobimetallic species, [Ni(L1)<span class="hlt">Fe</span>Cp(CO)]PF6, 1, and [Ni(L2)<span class="hlt">Fe</span>Cp]I, 2, respectively. Binding of a <span class="hlt">Fe</span>(CO)3 fragment via reaction of square-planar [Ni(pdt)(dppe)] (dppe, 1,2-diphenylphosphinoethane; pdt2–, 1,3-propanedithiolate) with <span class="hlt">Fe</span>3(CO)12 or [<span class="hlt">Fe</span>(CO)3(BDA)] (BDA, benzylidene acetone) affords diamagnetic [(dppe)Ni(μ-pdt)<span class="hlt">Fe</span>(CO)3], 3, in which the Ni(II) center is bound tetrahedrally to two thiolate S-donors and to two P-donors. The complex [(dppe)Ni(μ-pdt)<span class="hlt">Fe</span>(CO)3], 3, reacts in solution via rearrangement to afford [(OC)Ni(μ-dppe)(μ-pdt)<span class="hlt">Fe</span>(CO)2], 4, in which one P-donor of dppe is bound to Ni and the other to <span class="hlt">Fe</span>, and a CO ligand has transferred from <span class="hlt">Fe</span> to Ni. Additionally, the syntheses of 3 and 4 afford the side products [(dppe)Ni(CO)2] and [(OC)3<span class="hlt">Fe(pdt)Fe</span>(CO)3] together with the trinuclear species [(dppe)(CO)<span class="hlt">Fe(μ-CO)(μ-pdt)Fe(μ-pdt)Fe</span>(CO)3], 5. Reaction of [Ni(pdt)(dppe)] with [<span class="hlt">Fe</span>Cp(CO)2I] in CH2Cl2 affords two products [(dppe)Ni(μ-pdt)<span class="hlt">Fe</span>Cp(CO)]PF6, 6, and [(dppe)Ni(pdt)(μ-I)Ni(dppe)]PF6, 7. The complexes 2, 3, and 4 show Ni–<span class="hlt">Fe</span> distances of 2.539(4), 2.4666(6), and 2.4777(7) Å, respectively, with relatively acute dihedral angles of 79.5–81.8° for the Ni–S2-<span class="hlt">Fe</span> bridge, thus mimicking the shortened Ni...<span class="hlt">Fe</span> distance (2.5 Å) and the acute dihedral angle of the Ni–S2–<span class="hlt">Fe</span> moiety observed in certain active forms of [Ni<span class="hlt">Fe</span>]hydrogenase. The role of direct Ni–<span class="hlt">Fe</span> bonding in these complexes is discussed and linked to electronic structure calculations on [(dppe)Ni(pdt)<span class="hlt">Fe</span>(CO)3], 3, which confirm the presence of a bent Ni(dz2)-<span class="hlt">Fe</span>(dz2) σ-bond in a singlet ground state. PMID:16352727</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E%26PSL.473...94M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26PSL.473...94M"><span><span class="hlt">Fe-Fe</span>O and <span class="hlt">Fe-Fe</span>3C melting relations at Earth's core-mantle boundary conditions: Implications for a volatile-rich or oxygen-rich core</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morard, G.; Andrault, D.; Antonangeli, D.; Nakajima, Y.; Auzende, A. L.; Boulard, E.; Cervera, S.; Clark, A.; Lord, O. T.; Siebert, J.; Svitlyk, V.; Garbarino, G.; Mezouar, M.</p> <p>2017-09-01</p> <p>Eutectic melting temperatures in the <span class="hlt">Fe-Fe</span>O and <span class="hlt">Fe-Fe</span>3C systems have been determined up to 150 GPa. Melting criteria include observation of a diffuse scattering signal by in situ X-Ray diffraction, and textural characterisation of recovered samples. In addition, compositions of eutectic liquids have been established by combining in situ Rietveld analyses with ex situ chemical analyses. Gathering these new results together with previous reports on <span class="hlt">Fe</span>-S and <span class="hlt">Fe</span>-Si systems allow us to discuss the specific effect of each light element (Si, S, O, C) on the melting properties of the outer core. Crystallization temperatures of Si-rich core compositional <span class="hlt">models</span> are too high to be compatible with the absence of extensive mantle melting at the core-mantle boundary (CMB) and significant amounts of volatile elements such as S and/or C (>5 at%, corresponding to >2 wt%), or a large amount of O (>15 at% corresponding to ∼5 wt%) are required to reduce the crystallisation temperature of the core material below that of a peridotitic lower mantle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4755533','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4755533"><span>Assessing Discriminative Performance at External <span class="hlt">Validation</span> of Clinical Prediction <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nieboer, Daan; van der Ploeg, Tjeerd; Steyerberg, Ewout W.</p> <p>2016-01-01</p> <p>Introduction External <span class="hlt">validation</span> studies are essential to study the generalizability of prediction <span class="hlt">models</span>. Recently a permutation test, focusing on discrimination as quantified by the c-statistic, was proposed to judge whether a prediction <span class="hlt">model</span> is transportable to a new setting. We aimed to evaluate this test and compare it to previously proposed procedures to judge any changes in c-statistic from development to external <span class="hlt">validation</span> setting. Methods We compared the use of the permutation test to the use of benchmark values of the c-statistic following from a previously proposed framework to judge transportability of a prediction <span class="hlt">model</span>. In a simulation study we developed a prediction <span class="hlt">model</span> with logistic regression on a development set and <span class="hlt">validated</span> them in the <span class="hlt">validation</span> set. We concentrated on two scenarios: 1) the case-mix was more heterogeneous and predictor effects were weaker in the <span class="hlt">validation</span> set compared to the development set, and 2) the case-mix was less heterogeneous in the <span class="hlt">validation</span> set and predictor effects were identical in the <span class="hlt">validation</span> and development set. Furthermore we illustrated the methods in a case study using 15 datasets of patients suffering from traumatic brain injury. Results The permutation test indicated that the <span class="hlt">validation</span> and development set were homogenous in scenario 1 (in almost all simulated samples) and heterogeneous in scenario 2 (in 17%-39% of simulated samples). Previously proposed benchmark values of the c-statistic and the standard deviation of the linear predictors correctly pointed at the more heterogeneous case-mix in scenario 1 and the less heterogeneous case-mix in scenario 2. Conclusion The recently proposed permutation test may provide misleading results when externally <span class="hlt">validating</span> prediction <span class="hlt">models</span> in the presence of case-mix differences between the development and <span class="hlt">validation</span> population. To correctly interpret the c-statistic found at external <span class="hlt">validation</span> it is crucial to disentangle case-mix differences from incorrect</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26881753','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26881753"><span>Assessing Discriminative Performance at External <span class="hlt">Validation</span> of Clinical Prediction <span class="hlt">Models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nieboer, Daan; van der Ploeg, Tjeerd; Steyerberg, Ewout W</p> <p>2016-01-01</p> <p>External <span class="hlt">validation</span> studies are essential to study the generalizability of prediction <span class="hlt">models</span>. Recently a permutation test, focusing on discrimination as quantified by the c-statistic, was proposed to judge whether a prediction <span class="hlt">model</span> is transportable to a new setting. We aimed to evaluate this test and compare it to previously proposed procedures to judge any changes in c-statistic from development to external <span class="hlt">validation</span> setting. We compared the use of the permutation test to the use of benchmark values of the c-statistic following from a previously proposed framework to judge transportability of a prediction <span class="hlt">model</span>. In a simulation study we developed a prediction <span class="hlt">model</span> with logistic regression on a development set and <span class="hlt">validated</span> them in the <span class="hlt">validation</span> set. We concentrated on two scenarios: 1) the case-mix was more heterogeneous and predictor effects were weaker in the <span class="hlt">validation</span> set compared to the development set, and 2) the case-mix was less heterogeneous in the <span class="hlt">validation</span> set and predictor effects were identical in the <span class="hlt">validation</span> and development set. Furthermore we illustrated the methods in a case study using 15 datasets of patients suffering from traumatic brain injury. The permutation test indicated that the <span class="hlt">validation</span> and development set were homogenous in scenario 1 (in almost all simulated samples) and heterogeneous in scenario 2 (in 17%-39% of simulated samples). Previously proposed benchmark values of the c-statistic and the standard deviation of the linear predictors correctly pointed at the more heterogeneous case-mix in scenario 1 and the less heterogeneous case-mix in scenario 2. The recently proposed permutation test may provide misleading results when externally <span class="hlt">validating</span> prediction <span class="hlt">models</span> in the presence of case-mix differences between the development and <span class="hlt">validation</span> population. To correctly interpret the c-statistic found at external <span class="hlt">validation</span> it is crucial to disentangle case-mix differences from incorrect regression coefficients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20878895','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20878895"><span>Hypothesis testing for the <span class="hlt">validation</span> of the kinetic spectrophotometric methods for the determination of lansoprazole in bulk and drug formulations via <span class="hlt">Fe</span>(III) and Zn(II) chelates.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rahman, Nafisur; Kashif, Mohammad</p> <p>2010-03-01</p> <p>Point and interval hypothesis tests performed to <span class="hlt">validate</span> two simple and economical, kinetic spectrophotometric methods for the assay of lansoprazole are described. The methods are based on the formation of chelate complex of the drug with <span class="hlt">Fe</span>(III) and Zn(II). The reaction is followed spectrophotometrically by measuring the rate of change of absorbance of coloured chelates of the drug with <span class="hlt">Fe</span>(III) and Zn(II) at 445 and 510 nm, respectively. The stoichiometric ratio of lansoprazole to <span class="hlt">Fe</span>(III) and Zn(II) complexes were found to be 1:1 and 2:1, respectively. The initial-rate and fixed-time methods are adopted for determination of drug concentrations. The calibration graphs are linear in the range 50-200 µg ml⁻¹ (initial-rate method), 20-180 µg ml⁻¹ (fixed-time method) for lansoprazole-<span class="hlt">Fe</span>(III) complex and 120-300 (initial-rate method), and 90-210 µg ml⁻¹ (fixed-time method) for lansoprazole-Zn(II) complex. The inter-day and intra-day precision data showed good accuracy and precision of the proposed procedure for analysis of lansoprazole. The point and interval hypothesis tests indicate that the proposed procedures are not biased. Copyright © 2010 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MMTA..tmp.1423K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MMTA..tmp.1423K"><span>Kinetic Investigation and Wear Properties of <span class="hlt">Fe</span>2B Layers on AISI 12L14 Steel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keddam, M.; Ortiz-Dominguez, M.; Elias-Espinosa, M.; Arenas-Flores, A.; Zuno-Silva, J.; Zamarripa-Zepeda, D.; Gomez-Vargas, O. A.</p> <p>2018-03-01</p> <p>In the current study, the powder-pack boriding was applied to the AISI 12L14 steel in the temperature range 1123 K to 1273 K for an exposure time between 2 and 8 hours. The produced boride layer was composed of <span class="hlt">Fe</span>2B with a sawtooth morphology. A diffusion <span class="hlt">model</span> based on the integral method was applied to investigate the growth kinetics of <span class="hlt">Fe</span>2B layers. As a main result, the boron diffusion coefficients in <span class="hlt">Fe</span>2B were estimated by considering the principle of mass balance at the (<span class="hlt">Fe</span>2B/substrate) interface with an inclusion of boride incubation times. The value of activation energy for boron diffusion in AISI 12L14 steel was estimated as 165 kJ mol-1 and compared with other values of activation energy found in the literature. An experimental <span class="hlt">validation</span> of the present <span class="hlt">model</span> was made by using four different boriding conditions. Furthermore, the Rockwell-C adhesion test was employed to assess the cohesion of boride layers to the base metal. The scratch and pin-on-disc tests were also carried out to analyze the effect of boriding on wear behavior of AISI 12L14 steel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24678909','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24678909"><span>Cross-<span class="hlt">validation</span> pitfalls when selecting and assessing regression and classification <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krstajic, Damjan; Buturovic, Ljubomir J; Leahy, David E; Thomas, Simon</p> <p>2014-03-29</p> <p>We address the problem of selecting and assessing classification and regression <span class="hlt">models</span> using cross-<span class="hlt">validation</span>. Current state-of-the-art methods can yield <span class="hlt">models</span> with high variance, rendering them unsuitable for a number of practical applications including QSAR. In this paper we describe and evaluate best practices which improve reliability and increase confidence in selected <span class="hlt">models</span>. A key operational component of the proposed methods is cloud computing which enables routine use of previously infeasible approaches. We describe in detail an algorithm for repeated grid-search V-fold cross-<span class="hlt">validation</span> for parameter tuning in classification and regression, and we define a repeated nested cross-<span class="hlt">validation</span> algorithm for <span class="hlt">model</span> assessment. As regards variable selection and parameter tuning we define two algorithms (repeated grid-search cross-<span class="hlt">validation</span> and double cross-<span class="hlt">validation</span>), and provide arguments for using the repeated grid-search in the general case. We show results of our algorithms on seven QSAR datasets. The variation of the prediction performance, which is the result of choosing different splits of the dataset in V-fold cross-<span class="hlt">validation</span>, needs to be taken into account when selecting and assessing classification and regression <span class="hlt">models</span>. We demonstrate the importance of repeating cross-<span class="hlt">validation</span> when selecting an optimal <span class="hlt">model</span>, as well as the importance of repeating nested cross-<span class="hlt">validation</span> when assessing a prediction error.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1439974','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1439974"><span>Atomic-scale to Meso-scale Simulation Studies of Thermal Ageing and Irradiation Effects in <span class="hlt">Fe</span>- Cr Alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Stanley, Eugene; Liu, Li</p> <p></p> <p>In this project, we target at three primary objectives: (1) Molecular Dynamics (MD) code development for <span class="hlt">Fe</span>-Cr alloys, which can be utilized to provide thermodynamic and kinetic properties as inputs in mesoscale Phase Field (PF) simulations; (2) <span class="hlt">validation</span> and implementation of the MD code to explain thermal ageing and radiation damage; and (3) an integrated <span class="hlt">modeling</span> platform for MD and PF simulations. These two simulation tools, MD and PF, will ultimately be merged to understand and quantify the kinetics and mechanisms of microstructure and property evolution of <span class="hlt">Fe</span>-Cr alloys under various thermal and irradiation environments</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT........61C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT........61C"><span><span class="hlt">Validation</span> of Magnetospheric Magnetohydrodynamic <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Curtis, Brian</p> <p></p> <p>Magnetospheric magnetohydrodynamic (MHD) <span class="hlt">models</span> are commonly used for both prediction and <span class="hlt">modeling</span> of Earth's magnetosphere. To date, very little <span class="hlt">validation</span> has been performed to determine their limits, uncertainties, and differences. In this work, we performed a comprehensive analysis using several commonly used <span class="hlt">validation</span> techniques in the atmospheric sciences to MHD-based <span class="hlt">models</span> of Earth's magnetosphere for the first time. The <span class="hlt">validation</span> techniques of parameter variability/sensitivity analysis and comparison to other <span class="hlt">models</span> were used on the OpenGGCM, BATS-R-US, and SWMF magnetospheric MHD <span class="hlt">models</span> to answer several questions about how these <span class="hlt">models</span> compare. The questions include: (1) the difference between the <span class="hlt">model</span>'s predictions prior to and following to a reversal of Bz in the upstream interplanetary field (IMF) from positive to negative, (2) the influence of the preconditioning duration, and (3) the differences between <span class="hlt">models</span> under extreme solar wind conditions. A differencing visualization tool was developed and used to address these three questions. We find: (1) For a reversal in IMF Bz from positive to negative, the OpenGGCM magnetopause is closest to Earth as it has the weakest magnetic pressure near-Earth. The differences in magnetopause positions between BATS-R-US and SWMF are explained by the influence of the ring current, which is included in SWMF. Densities are highest for SWMF and lowest for OpenGGCM. The OpenGGCM tail currents differ significantly from BATS-R-US and SWMF; (2) A longer preconditioning time allowed the magnetosphere to relax more, giving different positions for the magnetopause with all three <span class="hlt">models</span> before the IMF Bz reversal. There were differences greater than 100% for all three <span class="hlt">models</span> before the IMF Bz reversal. The differences in the current sheet region for the OpenGGCM were small after the IMF Bz reversal. The BATS-R-US and SWMF differences decreased after the IMF Bz reversal to near zero; (3) For extreme conditions in the solar</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996JAP....79.5841K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996JAP....79.5841K"><span>Origins of giant biquadratic coupling in Co<span class="hlt">Fe/Mn/CoFe</span> sandwich structures (abstract)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koon, Norman C.</p> <p>1996-04-01</p> <p>Recently Filipkowski et al. reported extremely strong, near 90 degree coupling of 2.5 erg/cm2 for epitaxial sandwiches of Co<span class="hlt">Fe/Mn/CoFe</span>, where the Co<span class="hlt">Fe</span> composition was chosen to be a good lattice match to Mn. Both Co<span class="hlt">Fe</span> and Mn have the bcc structure, but Mn is antiferromagnetic while Co<span class="hlt">Fe</span> is ferromagnetic. It was found that the data were very well described by a simple <span class="hlt">model</span> due to Slonczewski, in which the interlayer coupling is given by Fc=C+(φ1-φ2)2+C-(φ1-φ2-π)2. While this <span class="hlt">model</span> describes the data much better than the usual biquadratic form, it still does not connect directly to the microscopic origins of the effect. In the present work we seek to explain the results in terms of normal bilinear exchange and magnetocrystalline anisotropy, together with reasonable assumptions about the structure of the interfaces. We obtain excellent agreement with both the experimental results and the Slonczewski <span class="hlt">model</span> under the assumptions that at least one of the two Co<span class="hlt">Fe</span>/Mn interfaces is smooth (i.e., atomically flat) on a length scale comparable to or greater than the thickness of the Mn layer and at least one interface is rough on a scale less than approximately a domain wall thickness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040161552','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040161552"><span>Solar Sail <span class="hlt">Models</span> and Test Measurements Correspondence for <span class="hlt">Validation</span> Requirements Definition</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ewing, Anthony; Adams, Charles</p> <p>2004-01-01</p> <p>Solar sails are being developed as a mission-enabling technology in support of future NASA science missions. Current efforts have advanced solar sail technology sufficient to justify a flight <span class="hlt">validation</span> program. A primary objective of this activity is to test and <span class="hlt">validate</span> solar sail <span class="hlt">models</span> that are currently under development so that they may be used with confidence in future science mission development (e.g., scalable to larger sails). Both system and <span class="hlt">model</span> <span class="hlt">validation</span> requirements must be defined early in the program to guide design cycles and to ensure that relevant and sufficient test data will be obtained to conduct <span class="hlt">model</span> <span class="hlt">validation</span> to the level required. A process of <span class="hlt">model</span> identification, <span class="hlt">model</span> input/output documentation, <span class="hlt">model</span> sensitivity analyses, and test measurement correspondence is required so that decisions can be made to satisfy <span class="hlt">validation</span> requirements within program constraints.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1740368','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1740368"><span><span class="hlt">Validity</span> of empirical <span class="hlt">models</span> of exposure in asphalt paving</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Burstyn, I; Boffetta, P; Burr, G; Cenni, A; Knecht, U; Sciarra, G; Kromhout, H</p> <p>2002-01-01</p> <p>Aims: To investigate the <span class="hlt">validity</span> of empirical <span class="hlt">models</span> of exposure to bitumen fume and benzo(a)pyrene, developed for a historical cohort study of asphalt paving in Western Europe. Methods: <span class="hlt">Validity</span> was evaluated using data from the USA, Italy, and Germany not used to develop the original <span class="hlt">models</span>. Correlation between observed and predicted exposures was examined. Bias and precision were estimated. Results: <span class="hlt">Models</span> were imprecise. Furthermore, predicted bitumen fume exposures tended to be lower (-70%) than concentrations found during paving in the USA. This apparent bias might be attributed to differences between Western European and USA paving practices. Evaluation of the <span class="hlt">validity</span> of the benzo(a)pyrene exposure <span class="hlt">model</span> revealed a similar to expected effect of re-paving and a larger than expected effect of tar use. Overall, benzo(a)pyrene <span class="hlt">models</span> underestimated exposures by 51%. Conclusions: Possible bias as a result of underestimation of the impact of coal tar on benzo(a)pyrene exposure levels must be explored in sensitivity analysis of the exposure–response relation. <span class="hlt">Validation</span> of the <span class="hlt">models</span>, albeit limited, increased our confidence in their applicability to exposure assessment in the historical cohort study of cancer risk among asphalt workers. PMID:12205236</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPSJ...84i3703H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPSJ...84i3703H"><span>Ab initio Studies of Magnetism in the Iron Chalcogenides <span class="hlt">Fe</span>Te and <span class="hlt">Fe</span>Se</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirayama, Motoaki; Misawa, Takahiro; Miyake, Takashi; Imada, Masatoshi</p> <p>2015-09-01</p> <p>The iron chalcogenides <span class="hlt">Fe</span>Te and <span class="hlt">Fe</span>Se belong to the family of iron-based superconductors. We study the magnetism in these compounds in the normal state using the ab initio downfolding scheme developed for strongly correlated electron systems. In deriving ab initio low-energy effective <span class="hlt">models</span>, we employ the constrained GW method to eliminate the double counting of electron correlations originating from the exchange correlations already taken into account in the density functional theory. By solving the derived ab initio effective <span class="hlt">models</span>, we reveal that the elimination of the double counting is important in reproducing the bicollinear antiferromagnetic order in <span class="hlt">Fe</span>Te, as is observed in experiments. We also show that the elimination of the double counting induces a unique degeneracy of several magnetic orders in <span class="hlt">Fe</span>Se, which may explain the absence of the magnetic ordering. We discuss the relationship between the degeneracy and the recently found puzzling phenomena in <span class="hlt">Fe</span>Se as well as the magnetic ordering found under pressure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26891250','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26891250"><span>Finite element <span class="hlt">models</span> of the human shoulder complex: a review of their clinical implications and <span class="hlt">modelling</span> techniques.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zheng, Manxu; Zou, Zhenmin; Bartolo, Paulo Jorge Da Silva; Peach, Chris; Ren, Lei</p> <p>2017-02-01</p> <p>The human shoulder is a complicated musculoskeletal structure and is a perfect compromise between mobility and stability. The objective of this paper is to provide a thorough review of previous finite element (<span class="hlt">FE</span>) studies in biomechanics of the human shoulder complex. Those <span class="hlt">FE</span> studies to investigate shoulder biomechanics have been reviewed according to the physiological and clinical problems addressed: glenohumeral joint stability, rotator cuff tears, joint capsular and labral defects and shoulder arthroplasty. The major findings, limitations, potential clinical applications and <span class="hlt">modelling</span> techniques of those <span class="hlt">FE</span> studies are critically discussed. The main challenges faced in order to accurately represent the realistic physiological functions of the shoulder mechanism in <span class="hlt">FE</span> simulations involve (1) subject-specific representation of the anisotropic nonhomogeneous material properties of the shoulder tissues in both healthy and pathological conditions; (2) definition of boundary and loading conditions based on individualised physiological data; (3) more comprehensive <span class="hlt">modelling</span> describing the whole shoulder complex including appropriate three-dimensional (3D) representation of all major shoulder hard tissues and soft tissues and their delicate interactions; (4) rigorous in vivo experimental <span class="hlt">validation</span> of <span class="hlt">FE</span> simulation results. Fully <span class="hlt">validated</span> shoulder <span class="hlt">FE</span> <span class="hlt">models</span> would greatly enhance our understanding of the aetiology of shoulder disorders, and hence facilitate the development of more efficient clinical diagnoses, non-surgical and surgical treatments, as well as shoulder orthotics and prosthetics. © 2016 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd. © 2016 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ISPAr.XL2...91D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ISPAr.XL2...91D"><span><span class="hlt">Validation</span> techniques of agent based <span class="hlt">modelling</span> for geospatial simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Darvishi, M.; Ahmadi, G.</p> <p>2014-10-01</p> <p>One of the most interesting aspects of <span class="hlt">modelling</span> and simulation study is to describe the real world phenomena that have specific properties; especially those that are in large scales and have dynamic and complex behaviours. Studying these phenomena in the laboratory is costly and in most cases it is impossible. Therefore, Miniaturization of world phenomena in the framework of a <span class="hlt">model</span> in order to simulate the real phenomena is a reasonable and scientific approach to understand the world. Agent-based <span class="hlt">modelling</span> and simulation (ABMS) is a new <span class="hlt">modelling</span> method comprising of multiple interacting agent. They have been used in the different areas; for instance, geographic information system (GIS), biology, economics, social science and computer science. The emergence of ABM toolkits in GIS software libraries (e.g. ESRI's ArcGIS, OpenMap, GeoTools, etc) for geospatial <span class="hlt">modelling</span> is an indication of the growing interest of users to use of special capabilities of ABMS. Since ABMS is inherently similar to human cognition, therefore it could be built easily and applicable to wide range applications than a traditional simulation. But a key challenge about ABMS is difficulty in their <span class="hlt">validation</span> and verification. Because of frequent emergence patterns, strong dynamics in the system and the complex nature of ABMS, it is hard to <span class="hlt">validate</span> and verify ABMS by conventional <span class="hlt">validation</span> methods. Therefore, attempt to find appropriate <span class="hlt">validation</span> techniques for ABM seems to be necessary. In this paper, after reviewing on Principles and Concepts of ABM for and its applications, the <span class="hlt">validation</span> techniques and challenges of ABM <span class="hlt">validation</span> are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140011905','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140011905"><span>A Formal Approach to Empirical Dynamic <span class="hlt">Model</span> Optimization and <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crespo, Luis G; Morelli, Eugene A.; Kenny, Sean P.; Giesy, Daniel P.</p> <p>2014-01-01</p> <p>A framework was developed for the optimization and <span class="hlt">validation</span> of empirical dynamic <span class="hlt">models</span> subject to an arbitrary set of <span class="hlt">validation</span> criteria. The <span class="hlt">validation</span> requirements imposed upon the <span class="hlt">model</span>, which may involve several sets of input-output data and arbitrary specifications in time and frequency domains, are used to determine if <span class="hlt">model</span> predictions are within admissible error limits. The parameters of the empirical <span class="hlt">model</span> are estimated by finding the parameter realization for which the smallest of the margins of requirement compliance is as large as possible. The uncertainty in the value of this estimate is characterized by studying the set of <span class="hlt">model</span> parameters yielding predictions that comply with all the requirements. Strategies are presented for bounding this set, studying its dependence on admissible prediction error set by the analyst, and evaluating the sensitivity of the <span class="hlt">model</span> predictions to parameter variations. This information is instrumental in characterizing uncertainty <span class="hlt">models</span> used for evaluating the dynamic <span class="hlt">model</span> at operating conditions differing from those used for its identification and <span class="hlt">validation</span>. A practical example based on the short period dynamics of the F-16 is used for illustration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH34B..02R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH34B..02R"><span>An Approach to Comprehensive and Sustainable Solar Wind <span class="hlt">Model</span> <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rastaetter, L.; MacNeice, P. J.; Mays, M. L.; Boblitt, J. M.; Wiegand, C.</p> <p>2017-12-01</p> <p>The number of <span class="hlt">models</span> of the corona and inner heliosphere and of their updates and upgrades grows steadily, as does the number and character of the <span class="hlt">model</span> inputs. Maintaining up to date <span class="hlt">validation</span> of these <span class="hlt">models</span>, in the face of this constant <span class="hlt">model</span> evolution, is a necessary but very labor intensive activity. In the last year alone, both NASA's LWS program and the CCMC's ongoing support of <span class="hlt">model</span> forecasting activities at NOAA SWPC have sought <span class="hlt">model</span> <span class="hlt">validation</span> reports on the quality of all aspects of the community's coronal and heliospheric <span class="hlt">models</span>, including both ambient and CME related wind solutions at L1. In this presentation I will give a brief review of the community's previous <span class="hlt">model</span> <span class="hlt">validation</span> results of L1 wind representation. I will discuss the semi-automated web based system we are constructing at the CCMC to present comparative visualizations of all interesting aspects of the solutions from competing <span class="hlt">models</span>.This system is designed to be easily queried to provide the essential comprehensive inputs to repeat andupdate previous <span class="hlt">validation</span> studies and support extensions to them. I will illustrate this by demonstrating how the system is being used to support the CCMC/LWS <span class="hlt">Model</span> Assessment Forum teams focused on the ambient and time dependent corona and solar wind, including CME arrival time and IMF Bz.I will also discuss plans to extend the system to include results from the Forum teams addressing SEP <span class="hlt">model</span> <span class="hlt">validation</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040086738','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040086738"><span>Parameterization of <span class="hlt">Model</span> <span class="hlt">Validating</span> Sets for Uncertainty Bound Optimizations. Revised</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lim, K. B.; Giesy, D. P.</p> <p>2000-01-01</p> <p>Given measurement data, a nominal <span class="hlt">model</span> and a linear fractional transformation uncertainty structure with an allowance on unknown but bounded exogenous disturbances, easily computable tests for the existence of a <span class="hlt">model</span> <span class="hlt">validating</span> uncertainty set are given. Under mild conditions, these tests are necessary and sufficient for the case of complex, nonrepeated, block-diagonal structure. For the more general case which includes repeated and/or real scalar uncertainties, the tests are only necessary but become sufficient if a collinearity condition is also satisfied. With the satisfaction of these tests, it is shown that a parameterization of all <span class="hlt">model</span> <span class="hlt">validating</span> sets of plant <span class="hlt">models</span> is possible. The new parameterization is used as a basis for a systematic way to construct or perform uncertainty tradeoff with <span class="hlt">model</span> <span class="hlt">validating</span> uncertainty sets which have specific linear fractional transformation structure for use in robust control design and analysis. An illustrative example which includes a comparison of candidate <span class="hlt">model</span> <span class="hlt">validating</span> sets is given.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040034122','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040034122"><span><span class="hlt">Validation</span> of the Poisson Stochastic Radiative Transfer <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhuravleva, Tatiana; Marshak, Alexander</p> <p>2004-01-01</p> <p>A new approach to <span class="hlt">validation</span> of the Poisson stochastic radiative transfer method is proposed. In contrast to other <span class="hlt">validations</span> of stochastic <span class="hlt">models</span>, the main parameter of the Poisson <span class="hlt">model</span> responsible for cloud geometrical structure - cloud aspect ratio - is determined entirely by matching measurements and calculations of the direct solar radiation. If the measurements of the direct solar radiation is unavailable, it was shown that there is a range of the aspect ratios that allows the stochastic <span class="hlt">model</span> to accurately approximate the average measurements of surface downward and cloud top upward fluxes. Realizations of the fractionally integrated cascade <span class="hlt">model</span> are taken as a prototype of real measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017npjQM...2...20K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017npjQM...2...20K"><span>Realizing Haldane <span class="hlt">model</span> in <span class="hlt">Fe</span>-based honeycomb ferromagnetic insulators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Heung-Sik; Kee, Hae-Young</p> <p>2017-12-01</p> <p>The topological Haldane <span class="hlt">model</span> on a honeycomb lattice is a prototype of systems hosting topological phases of matter without external fields. It is the simplest <span class="hlt">model</span> exhibiting the quantum Hall effect without Landau levels, which motivated theoretical and experimental explorations of topological insulators and superconductors. Despite its simplicity, its realization in condensed matter systems has been elusive due to a seemingly difficult condition of spinless fermions with sublattice-dependent magnetic flux terms. While there have been theoretical proposals including elaborate atomic-scale engineering, identifying candidate topological Haldane <span class="hlt">model</span> materials has not been successful, and the first experimental realization was recently made in ultracold atoms. Here, we suggest that a series of <span class="hlt">Fe</span>-based honeycomb ferromagnetic insulators, AFe2(PO4)2 (A=Ba, Cs, K, La) possess Chern bands described by the topological Haldane <span class="hlt">model</span>. How to detect the quantum anomalous Hall effect is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26660529','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26660529"><span>AdViSHE: A <span class="hlt">Validation</span>-Assessment Tool of Health-Economic <span class="hlt">Models</span> for Decision Makers and <span class="hlt">Model</span> Users.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vemer, P; Corro Ramos, I; van Voorn, G A K; Al, M J; Feenstra, T L</p> <p>2016-04-01</p> <p>A trade-off exists between building confidence in health-economic (HE) decision <span class="hlt">models</span> and the use of scarce resources. We aimed to create a practical tool providing <span class="hlt">model</span> users with a structured view into the <span class="hlt">validation</span> status of HE decision <span class="hlt">models</span>, to address this trade-off. A Delphi panel was organized, and was completed by a workshop during an international conference. The proposed tool was constructed iteratively based on comments from, and the discussion amongst, panellists. During the Delphi process, comments were solicited on the importance and feasibility of possible <span class="hlt">validation</span> techniques for <span class="hlt">modellers</span>, their relevance for decision makers, and the overall structure and formulation in the tool. The panel consisted of 47 experts in HE <span class="hlt">modelling</span> and HE decision making from various professional and international backgrounds. In addition, 50 discussants actively engaged in the discussion at the conference workshop and returned 19 questionnaires with additional comments. The final version consists of 13 items covering all relevant aspects of HE decision <span class="hlt">models</span>: the conceptual <span class="hlt">model</span>, the input data, the implemented software program, and the <span class="hlt">model</span> outcomes. Assessment of the <span class="hlt">Validation</span> Status of Health-Economic decision <span class="hlt">models</span> (AdViSHE) is a <span class="hlt">validation</span>-assessment tool in which <span class="hlt">model</span> developers report in a systematic way both on <span class="hlt">validation</span> efforts performed and on their outcomes. Subsequently, <span class="hlt">model</span> users can establish whether confidence in the <span class="hlt">model</span> is justified or whether additional <span class="hlt">validation</span> efforts should be undertaken. In this way, AdViSHE enhances transparency of the <span class="hlt">validation</span> status of HE <span class="hlt">models</span> and supports efficient <span class="hlt">model</span> <span class="hlt">validation</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5708595','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5708595"><span>Geographic and temporal <span class="hlt">validity</span> of prediction <span class="hlt">models</span>: Different approaches were useful to examine <span class="hlt">model</span> performance</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Austin, Peter C.; van Klaveren, David; Vergouwe, Yvonne; Nieboer, Daan; Lee, Douglas S.; Steyerberg, Ewout W.</p> <p>2017-01-01</p> <p>Objective <span class="hlt">Validation</span> of clinical prediction <span class="hlt">models</span> traditionally refers to the assessment of <span class="hlt">model</span> performance in new patients. We studied different approaches to geographic and temporal <span class="hlt">validation</span> in the setting of multicenter data from two time periods. Study Design and Setting We illustrated different analytic methods for <span class="hlt">validation</span> using a sample of 14,857 patients hospitalized with heart failure at 90 hospitals in two distinct time periods. Bootstrap resampling was used to assess internal <span class="hlt">validity</span>. Meta-analytic methods were used to assess geographic transportability. Each hospital was used once as a <span class="hlt">validation</span> sample, with the remaining hospitals used for <span class="hlt">model</span> derivation. Hospital-specific estimates of discrimination (c-statistic) and calibration (calibration intercepts and slopes) were pooled using random effects meta-analysis methods. I2 statistics and prediction interval width quantified geographic transportability. Temporal transportability was assessed using patients from the earlier period for <span class="hlt">model</span> derivation and patients from the later period for <span class="hlt">model</span> <span class="hlt">validation</span>. Results Estimates of reproducibility, pooled hospital-specific performance, and temporal transportability were on average very similar, with c-statistics of 0.75. Between-hospital variation was moderate according to I2 statistics and prediction intervals for c-statistics. Conclusion This study illustrates how performance of prediction <span class="hlt">models</span> can be assessed in settings with multicenter data at different time periods. PMID:27262237</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeCoA.186...71V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeCoA.186...71V"><span><span class="hlt">Fe</span> hydroxyphosphate precipitation and <span class="hlt">Fe</span>(II) oxidation kinetics upon aeration of <span class="hlt">Fe</span>(II) and phosphate-containing synthetic and natural solutions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van der Grift, B.; Behrends, T.; Osté, L. A.; Schot, P. P.; Wassen, M. J.; Griffioen, J.</p> <p>2016-08-01</p> <p> natural groundwater showed no principal differences in <span class="hlt">Fe</span>(II) oxidation kinetics and in PO4 immobilisation dynamics compared with synthetic solutions with corresponding P/<span class="hlt">Fe</span> ratio, pH and oxygen pressure. However, aeration of groundwater with relative high DOC concentrations and a low salinity lead to P-rich <span class="hlt">Fe</span> colloids that were colloidally stable. The formation of a <span class="hlt">Fe</span> hydroxyphosphate phase with a molar P/<span class="hlt">Fe</span> ratio of 0.6 can be used for predictive <span class="hlt">modelling</span> of PO4 immobilisation upon aeration of pH-neutral natural groundwater with an (P/<span class="hlt">Fe</span>)ini ratio up to 1.5. These findings provide a solid basis for further studies on transport and bioavailability of phosphorus in streams, ditches and channels that receive anoxic <span class="hlt">Fe</span>-rich groundwater.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3837848','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3837848"><span>Gallium Nitrate Is Efficacious in Murine <span class="hlt">Models</span> of Tuberculosis and Inhibits Key Bacterial <span class="hlt">Fe</span>-Dependent Enzymes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Olakanmi, Oyebode; Kesavalu, Banurekha; Pasula, Rajamouli; Abdalla, Maher Y.; Schlesinger, Larry S.</p> <p>2013-01-01</p> <p>Acquiring iron (<span class="hlt">Fe</span>) is critical to the metabolism and growth of Mycobacterium tuberculosis. Disruption of <span class="hlt">Fe</span> metabolism is a potential approach for novel antituberculous therapy. Gallium (Ga) has many similarities to <span class="hlt">Fe</span>. Biological systems are often unable to distinguish Ga3+ from <span class="hlt">Fe</span>3+. Unlike <span class="hlt">Fe</span>3+, Ga3+ cannot be physiologically reduced to Ga2+. Thus, substituting Ga for <span class="hlt">Fe</span> in the active site of enzymes may render them nonfunctional. We previously showed that Ga inhibits growth of M. tuberculosis in broth and within cultured human macrophages. We now report that Ga(NO3)3 shows efficacy in murine tuberculosis <span class="hlt">models</span>. BALB/c SCID mice were infected intratracheally with M. tuberculosis, following which they received daily intraperitoneal saline, Ga(NO3)3, or NaNO3. All mice receiving saline or NaNO3 died. All Ga(NO3)3-treated mice survived. M. tuberculosis CFU in the lungs, liver, and spleen of the NaNO3-treated or saline-treated mice were significantly higher than those in Ga-treated mice. When BALB/c mice were substituted for BALB/c SCID mice as a chronic (nonlethal) infection <span class="hlt">model</span>, Ga(NO3)3 treatment significantly decreased lung CFU. To assess the mechanism(s) whereby Ga inhibits bacterial growth, the effect of Ga on M. tuberculosis ribonucleotide reductase (RR) (a key enzyme in DNA replication) and aconitase activities was assessed. Ga decreased M. tuberculosis RR activity by 50 to 60%, but no additional decrease in RR activity was seen at Ga concentrations that completely inhibited mycobacterial growth. Ga decreased aconitase activity by 90%. Ga(NO3)3 shows efficacy in murine M. tuberculosis infection and leads to a decrease in activity of <span class="hlt">Fe</span>-dependent enzymes. Additional work is warranted to further define Ga's mechanism of action and to optimize delivery forms for possible therapeutic uses in humans. PMID:24060870</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4177079','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4177079"><span>A Novel Rat <span class="hlt">Model</span> of Orthodontic Tooth Movement Using Temporary Skeletal Anchorage Devices: 3D Finite Element Analysis and In Vivo <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Stevenson, Thomas; Doschak, Michael</p> <p>2014-01-01</p> <p>The aim of this animal study was to develop a <span class="hlt">model</span> of orthodontic tooth movement using a microimplant as a TSAD in rodents. A finite element <span class="hlt">model</span> of the TSAD in alveolar bone was built using μCT images of rat maxilla to determine the von Mises stresses and displacement in the alveolar bone surrounding the TSAD. For in vivo <span class="hlt">validation</span> of the <span class="hlt">FE</span> <span class="hlt">model</span>, Sprague-Dawley rats (n = 25) were used and a Stryker 1.2 × 3 mm microimplant was inserted in the right maxilla and used to protract the right first permanent molar using a NiTi closed coil spring. Tooth movement measurements were taken at baseline, 4 and 8 weeks. At 8 weeks, animals were euthanized and tissues were analyzed by histology and EPMA. <span class="hlt">FE</span> <span class="hlt">modeling</span> showed maximum von Mises stress of 45 Mpa near the apex of TSAD but the average von Mises stress was under 25 Mpa. Appreciable tooth movement of 0.62 ± 0.04 mm at 4 weeks and 1.99 ± 0.14 mm at 8 weeks was obtained. Histological and EPMA results demonstrated no active bone remodeling around the TSAD at 8 weeks depicting good secondary stability. This study provided evidence that protracted tooth movement is achieved in small animals using TSADs. PMID:25295060</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008HyInt.185...47S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008HyInt.185...47S"><span>Dimeric <span class="hlt">Fe</span> (II, III) complex of quinoneoxime as functional <span class="hlt">model</span> of PAP enzyme: Mössbauer, magneto-structural and DNA cleavage studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salunke-Gawali, Sunita; Ahmed, Khursheed; Varret, François; Linares, Jorge; Zaware, Santosh; Date, Sadgopal; Rane, Sandhya</p> <p>2008-07-01</p> <p>Purple acid phosphatase, ( PAP), is known to contain dinuclear <span class="hlt">Fe</span>2 + 2, + 3 site with characteristic <span class="hlt">Fe</span> + 3 ← Tyr ligand to metal charge transfer in coordination. Phthiocoloxime (3-methyl-2-hydroxy-1,4-naphthoquinone-1-oxime) ligand L, mimics (His/Tyr) ligation with controlled and unique charge transfers resulting in valence tautomeric coordination with mixed valent diiron site in <span class="hlt">model</span> compound <span class="hlt">Fe</span>-1: [μ-OH-<span class="hlt">Fe</span>2 + 2, + 3 ( o-NQCH3ox) ( o-NSQCH3ox)2 (CAT) H2O]. <span class="hlt">Fe</span>-2: [<span class="hlt">Fe</span> + 3( o-NQCH3ox) ( p-NQCH3ox)2]2 a molecularly associated dimer of phthiocoloxime synthesized for comparison of charge transfer. 57<span class="hlt">Fe</span> Mössbauer studies was used to quantitize unusual valences due to ligand in dimeric <span class="hlt">Fe</span>-1 and <span class="hlt">Fe</span>-2 complexes which are supported by EPR and SQUID studies. 57<span class="hlt">Fe</span> Mössbauer spectra for <span class="hlt">Fe</span>-1 at 300 K indicates the presence of two quadrupole split asymmetric doublets due to the differences in local coordination geometries of [<span class="hlt">Fe</span> + 3]A and [<span class="hlt">Fe</span> + 2]B sites. The hyperfine interaction parameters are δ A = 0.152, (Δ E Q)A = 0.598 mm/s with overlapping doublet at δ B = 0.410 and (Δ E Q)B = 0.468 mm/s. Due to molecular association tendency of ligand, dimer <span class="hlt">Fe</span>-2 possesses 100% <span class="hlt">Fe</span> + 3(h.s.) hexacoordinated configuration with isomer shift δ = 0.408 mm/s. Slightly distorted octahedral symmetry created by NQCH3ox ligand surrounding <span class="hlt">Fe</span> + 3(h.s.) state generates small field gradient indicated by quadrupole split Δ E Q = 0.213 mm/s. Decrease of isomer shifts together with variation of quadrupole splits with temperature in <span class="hlt">Fe</span>-1 dimer compared to <span class="hlt">Fe</span>-2 is result of charge transfers in [<span class="hlt">Fe</span>2 + 2, + 3 SQ] complexes. EPR spectrum of <span class="hlt">Fe</span>-1 shows two strong signals at g 1 = 4.17 and g 2 = 2.01 indicative of S = 3/2 spin state with an intermediate spin of <span class="hlt">Fe</span> + 3(h.s.) configuration. SQUID data of χ _m^{corr} .T were best fitted by using HDVV spin pair <span class="hlt">model</span> S = 2, 3/2 resulting in antiferromagnetic exchange ( J = -13.5 cm - 1 with an agreement factor of R = 1.89 × 10 - 5). The lower J</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23132908W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23132908W"><span>Refractory Abundances of Terrestrial Planets and Their Stars: Testing [Si/<span class="hlt">Fe</span>] Correlations with TESS and PLATO</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wolfgang, Angie; Fortney, Jonathan</p> <p>2018-01-01</p> <p>In standard <span class="hlt">models</span> for planet formation, solid material in protoplanetary disks coagulate and collide to form rocky bodies. It therefore seems reasonable to assume that their chemical composition will follow the abundances of refractory elements, such as Si and <span class="hlt">Fe</span>, in the host star, which has also accreted material from the disk. Backed by planet formation simulations which <span class="hlt">validate</span> this assumption, planetary internal structure <span class="hlt">models</span> have begun to use stellar abundances to break degeneracies in low-mass planet compositions inferred only from mass and radius. Inconveniently, our own Solar System contradicts this approach, as its terrestrial bodies exhibit a range of rock/iron ratios and the Sun's [Si/<span class="hlt">Fe</span>] ratio is offset from the mean planetary [Si/<span class="hlt">Fe</span>]. In this work, we explore what number and quality of observations we need to empirically measure the exoplanet-star [Si/<span class="hlt">Fe</span>] correlation, given future transit missions, RV follow-up, and stellar characterization. Specifically, we generate synthetic datasets of terrestrial planet masses and radii and host star abundances assuming that the planets’ bulk [Si/<span class="hlt">Fe</span>] ratio exactly tracks that of their host stars. We assign measurement uncertainties corresponding to expected precisions for TESS, PLATO, Gaia, and future RV instrumentation, and then invert the problem to infer the planet-star [Si/<span class="hlt">Fe</span>] correlation given these observational constraints. Comparing the result to the generated truth, we find that 1% precision on the planet radii is needed to test whether [Si/<span class="hlt">Fe</span>] ratios are correlated between exoplanet and host star. On the other hand, lower precisions can test for systematic offsets between planet and star [Si/<span class="hlt">Fe</span>], which can constrain the importance of giant impacts for extrasolar terrestrial planet formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1834c0009L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1834c0009L"><span>Multi-body <span class="hlt">modeling</span> method for rollover using MADYMO</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Changye; Lin, Zhigui; Lv, Juncheng; Luo, Qinyue; Qin, Zhenyao; Zhang, Pu; Chen, Tao</p> <p>2017-04-01</p> <p>Rollovers are complex road accidents causing a big deal of fatalities. <span class="hlt">FE</span> <span class="hlt">model</span> for rollover study will costtoo much time due to its long duration.A new multi-body <span class="hlt">modeling</span> method is proposed in this paper which can save a lot of time and has high-fidelity meanwhile. Following works were carried out to <span class="hlt">validate</span> this new method. First, a small van was tested following the FMVSS 208 protocol for the <span class="hlt">validation</span> of the proposed <span class="hlt">modeling</span> method. Second, a MADYMO <span class="hlt">model</span> of this small van was reconstructed. The vehicle body was divided into two main parts, the deformable upper body and the rigid lower body, <span class="hlt">modeled</span> by different waysbased on an <span class="hlt">FE</span> <span class="hlt">model</span>. The specific method of <span class="hlt">modeling</span> is offered in this paper. Finally, the trajectories of the vehicle from test and simulation were comparedand the match was very good. Acceleration of left B pillar was taken into consideration, which turned out fitting the test result well in the time of event. The final deformation status of the vehicle in test and simulation showed similar trend. This <span class="hlt">validated</span> <span class="hlt">model</span> provides a reliable wayfor further research in occupant injuries during rollovers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28388447','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28388447"><span>Application of UV-irradiated <span class="hlt">Fe</span>(III)-nitrilotriacetic acid (UV-<span class="hlt">Fe</span>(III)NTA) and UV-NTA-Fenton systems to degrade <span class="hlt">model</span> and natural occurring naphthenic acids.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Ying; Chelme-Ayala, Pamela; Klamerth, Nikolaus; Gamal El-Din, Mohamed</p> <p>2017-07-01</p> <p>Naphthenic acids (NAs) are a highly complex mixture of organic compounds naturally present in bitumen and identified as the primary toxic constituent of oil sands process-affected water (OSPW). This work investigated the degradation of cyclohexanoic acid (CHA), a <span class="hlt">model</span> NA compound, and natural occurring NAs during the UV photolysis of <span class="hlt">Fe</span>(III)-nitrilotriacetic acid (UV-<span class="hlt">Fe</span>(III)NTA) and UV-NTA-Fenton processes. The results indicated that in the UV-<span class="hlt">Fe</span>(III)NTA process at pH 8, the CHA removal increased with increasing NTA dose (0.18, 0.36 and 0.72 mM), while it was independent of the <span class="hlt">Fe</span>(III) dose (0.09, 0.18 and 0.36 mM). Moreover, the three <span class="hlt">Fe</span> concentrations had no influence on the photolysis of the <span class="hlt">Fe</span>(III)NTA complex. The main responsible species for the CHA degradation was hydroxyl radical (OH), and the role of dissolved O 2 in the OH generation was found to be negligible. Real OSPW was treated with the UV-<span class="hlt">Fe</span>(III)NTA and UV-NTA-Fenton advanced oxidation processes (AOPs). The removals of classical NAs (O 2 -NAs), oxidized NAs with one additional oxygen atom (O 3 -NAs) and with two additional oxygen atoms (O 4 -NAs) were 44.5%, 21.3%, and 25.2% in the UV-<span class="hlt">Fe</span>(III)NTA process, respectively, and 98.4%, 86.0%, and 81.0% in the UV-NTA-Fenton process, respectively. There was no influence of O 2 on the NA removal in these two processes. The results also confirmed the high reactivity of the O 2 -NA species with more carbons and increasing number of rings or double bond equivalents. This work opens a new window for the possible treatment of OSPW at natural pH using these AOPs. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MolPh.115.2185A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MolPh.115.2185A"><span>Single metal catalysis: DFT and CAS <span class="hlt">modelling</span> of species involved in the <span class="hlt">Fe</span> cation assisted transformation of acetylene to benzene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Altun, Zikri; Bleda, Erdi; Trindle, Carl</p> <p>2017-09-01</p> <p>Gas phase conversion of acetylene to benzene, assisted by a single metal cation such as <span class="hlt">Fe</span>(+), Ru(+) and Rh(+), offers an attractive prospect for application of computational <span class="hlt">modelling</span> techniques to catalytic processes. Gas phase processes are not complicated by environmental effects and the participation of a single metal atom is a significant simplification. Still the process is complex, owing to the possibility of several low-energy spin states and the abundance of alternative structures. By density functional theory <span class="hlt">modelling</span> using recently developed <span class="hlt">models</span> with range and dispersion corrections, we locate and characterise a number of extreme points on the <span class="hlt">Fe</span>C6H6(+) surface, some of which have not been described previously. These include eta-1, eta-2 and eta-3 complexes of <span class="hlt">Fe</span>(+) with the C4H4 ring. We identify new <span class="hlt">Fe</span>C6H6(+) structures as well, which may be landmarks for the <span class="hlt">Fe</span>(+)-catalysed production of benzene from acetylene. The <span class="hlt">Fe</span>(+) benzene complex is the most stable species on the <span class="hlt">Fe</span>C6H6 cation surface. With the abundant energy of complexation available in the isolated gas phase species, detachment of the <span class="hlt">Fe</span>(+) and production of benzene can be efficient. We address the issue raised by other investigators whether multi-configurational self-consistent field methods are essential to the proper description of these systems. We find that the relative energy of intrinsically multi-determinant doublets is strongly affected, but judge that the density functional theory (DFT) description provides more accurate estimates of energetics and a more plausible reaction path.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1091948-virtual-model-validation-complex-multiscale-systems-applications-nonlinear-elastostatics','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1091948-virtual-model-validation-complex-multiscale-systems-applications-nonlinear-elastostatics"><span>Virtual <span class="hlt">Model</span> <span class="hlt">Validation</span> of Complex Multiscale Systems: Applications to Nonlinear Elastostatics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Oden, John Tinsley; Prudencio, Ernest E.; Bauman, Paul T.</p> <p></p> <p>We propose a virtual statistical <span class="hlt">validation</span> process as an aid to the design of experiments for the <span class="hlt">validation</span> of phenomenological <span class="hlt">models</span> of the behavior of material bodies, with focus on those cases in which knowledge of the fabrication process used to manufacture the body can provide information on the micro-molecular-scale properties underlying macroscale behavior. One example is given by <span class="hlt">models</span> of elastomeric solids fabricated using polymerization processes. We describe a framework for <span class="hlt">model</span> <span class="hlt">validation</span> that involves Bayesian updates of parameters in statistical calibration and <span class="hlt">validation</span> phases. The process enables the quanti cation of uncertainty in quantities of interest (QoIs) andmore » the determination of <span class="hlt">model</span> consistency using tools of statistical information theory. We assert that microscale information drawn from molecular <span class="hlt">models</span> of the fabrication of the body provides a valuable source of prior information on parameters as well as a means for estimating <span class="hlt">model</span> bias and designing virtual <span class="hlt">validation</span> experiments to provide information gain over calibration posteriors.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3105220','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3105220"><span>COMPARATIVE ASSESSMENT OF THE COMPOSITION AND CHARGE STATE OF NITROGENASE <span class="hlt">Fe</span>Mo-COFACTOR</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Harris, Travis V.; Szilagyi, Robert K.</p> <p>2011-01-01</p> <p>A significant limitation in our understanding of the molecular mechanism of biological nitrogen fixation is the uncertain composition of the <span class="hlt">Fe</span>Mo-cofactor (<span class="hlt">Fe</span>Mo-co) of nitrogenase. In this study we present a systematic, density functional theory-based evaluation of spin coupling schemes, iron oxidation states, ligand protonation states, and interstitial ligand composition using a wide range of experimental criteria. The employed functionals and basis sets were <span class="hlt">validated</span> with molecular orbital information from X-ray absorption spectroscopic data of relevant iron-sulfur clusters. Independently from the employed level of theory, the electronic structure with the greatest number of antiferromagnetic interactions corresponds to the lowest energy state for a given charge and oxidation state distribution of the iron ions. The relative spin state energies of resting and oxidized <span class="hlt">Fe</span>Mo-co already allowed the exclusion of certain iron oxidation state distributions and interstitial ligand compositions. Geometry optimized <span class="hlt">Fe</span>Mo-co structures of several <span class="hlt">models</span> further eliminated additional states and compositions, while reduction potentials indicated a strong preference for the most likely charge state of <span class="hlt">Fe</span>Mo-co. Mössbauer and ENDOR parameter calculations were found to be remarkably dependent on the employed training set, density functional and basis set. Overall, we found that a more oxidized [MoIV-2<span class="hlt">Fe</span>II-5<span class="hlt">Fe</span>III-9S2−-C4−] composition with a hydroxyl-protonated homocitrate ligand satisfies all of the available experimental criteria, and is thus favored over the currently preferred composition of [MoIV-4<span class="hlt">Fe</span>II-3<span class="hlt">Fe</span>III-9S2−-N3−] from the literature. PMID:21545160</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25747808','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25747808"><span>Novel reactions of homodinuclear Ni2 complexes [Ni(RNPyS4)]2 with <span class="hlt">Fe</span>3(CO)12 to give heterotrinuclear Ni<span class="hlt">Fe</span>2 and mononuclear <span class="hlt">Fe</span> complexes relevant to [Ni<span class="hlt">Fe</span>]- and [<span class="hlt">Fe</span>]-hydrogenases.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Song, Li-Cheng; Cao, Meng; Wang, Yong-Xiang</p> <p>2015-04-21</p> <p>The homodinuclear complexes [Ni(RNPyS4)]2 (; RNPyS4 = 2,6-bis(2-mercaptophenylthiomethyl)-4-R-pyridine; R = H, MeO, Cl, Br, i-Pr) were found to be prepared by reactions of the in situ generated Li2[Ni(1,2-S2C6H4)2] with 2,6-bis[(tosyloxy)methyl]pyridine and its substituted derivatives 2,6-bis[(tosyloxy)methyl]-4-R-pyridine. Further reactions of with <span class="hlt">Fe</span>3(CO)12 gave both heterotrinuclear complexes Ni<span class="hlt">Fe</span>2(RNPyS4)(CO)5 () and mononuclear complexes <span class="hlt">Fe</span>(RNPyS4)(CO) (), unexpectedly. Interestingly, complexes and could be regarded as <span class="hlt">models</span> for the active sites of [Ni<span class="hlt">Fe</span>]- and [<span class="hlt">Fe</span>]-hydrogenases, respectively. All the prepared complexes were characterized by elemental analysis, spectroscopy, and particularly for some of them, by X-ray crystallography. In addition, the electrochemical properties of and as well as the electrocatalytic H2 production catalyzed by and were investigated by CV techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28079958','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28079958"><span>An S-Oxygenated [Ni<span class="hlt">Fe</span>] Complex <span class="hlt">Modelling</span> Sulfenate Intermediates of an O2 -Tolerant Hydrogenase.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lindenmaier, Nils J; Wahlefeld, Stefan; Bill, Eckhard; Szilvási, Tibor; Eberle, Christopher; Yao, Shenglai; Hildebrandt, Peter; Horch, Marius; Zebger, Ingo; Driess, Matthias</p> <p>2017-02-13</p> <p>To understand the molecular details of O 2 -tolerant hydrogen cycling by a soluble NAD + -reducing [Ni<span class="hlt">Fe</span>] hydrogenase, we herein present the first bioinspired heterobimetallic S-oxygenated [Ni<span class="hlt">Fe</span>] complex as a structural and vibrational spectroscopic <span class="hlt">model</span> for the oxygen-inhibited [Ni<span class="hlt">Fe</span>] active site. This compound and its non-S-oxygenated congener were fully characterized, and their electronic structures were elucidated in a combined experimental and theoretical study with emphasis on the bridging sulfenato moiety. Based on the vibrational spectroscopic properties of these complexes, we also propose novel strategies for exploring S-oxygenated intermediates in hydrogenases and similar enzymes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2547486','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2547486"><span>Spectroscopic and Quantum Chemical Studies on low-spin <span class="hlt">Fe</span>IV=O complexes: <span class="hlt">Fe</span>-O bonding and its contributions to reactivity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Decker, Andrea; Rohde, Jan-Uwe; Klinker, Eric J.; Wong, Shaun D.; Que, Lawrence; Solomon, Edward I.</p> <p>2008-01-01</p> <p>High valent <span class="hlt">Fe</span>IV=O species are key intermediates in the catalytic cycles of many mononuclear non-heme iron enzymes and have been structurally defined in <span class="hlt">model</span> systems. Variable temperature magnetic circular dichroism (VT-MCD) spectroscopy has been used to evaluate the electronic structures and in particular the <span class="hlt">Fe</span>-O bonds of three <span class="hlt">Fe</span>IV=O (S=1) <span class="hlt">model</span> complexes, [<span class="hlt">Fe</span>IV(O)(TMC)(NCMe)]2+, [<span class="hlt">Fe</span>IV(O)(TMC)(OC(O)CF3)]+, and [<span class="hlt">Fe</span>IV(O)(N4Py)]2+. These complexes are characterized by their strong and covalent <span class="hlt">Fe</span>-O π-bonds. The MCD spectra show a vibronic progression in the non-bonding → π* excited state, providing the <span class="hlt">Fe</span>-O stretching frequency and the <span class="hlt">Fe</span>-O bond length in this excited state and quantifying the π-contribution to the total <span class="hlt">Fe</span>-O bond. Correlation of these experimental data to reactivity shows that the [<span class="hlt">Fe</span>IV(O)(N4Py)]2+ complex, with the highest reactivity towards hydrogen-atom abstraction among the three, has the strongest <span class="hlt">Fe</span>-O π-bond. Density Functional calculations were correlated to the data and support the experimental analysis. The strength and covalency of the <span class="hlt">Fe</span>-O π-bond result in high oxygen character in the important frontier molecular orbitals (FMOs) for this reaction, the unoccupied β-spin d(xz/yz) orbitals, and activates these for electrophilic attack. An extension to biologically relevant <span class="hlt">Fe</span>IV=O (S=2) enzyme intermediates shows that these can perform electrophilic attack reactions along the same mechanistic pathway (π-FMO pathway) with similar reactivity, but also have an additional reaction channel involving the unoccupied α-spin d(z2) orbital (σ-FMO pathway). These studies experimentally probe the FMOs involved in the reactivity of <span class="hlt">Fe</span>IV=O (S=1) <span class="hlt">model</span> complexes resulting in a detailed understanding of the <span class="hlt">Fe</span>-O bond and its contributions to reactivity. PMID:18052249</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22597776-magnetic-cluster-expansion-model-random-ordered-magnetic-face-centered-cubic-fe-ni-cr-alloys','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22597776-magnetic-cluster-expansion-model-random-ordered-magnetic-face-centered-cubic-fe-ni-cr-alloys"><span>Magnetic cluster expansion <span class="hlt">model</span> for random and ordered magnetic face-centered cubic <span class="hlt">Fe</span>-Ni-Cr alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lavrentiev, M. Yu., E-mail: Mikhail.Lavrentiev@ukaea.uk; Nguyen-Manh, D.; Dudarev, S. L.</p> <p></p> <p>A Magnetic Cluster Expansion <span class="hlt">model</span> for ternary face-centered cubic <span class="hlt">Fe</span>-Ni-Cr alloys has been developed, using DFT data spanning binary and ternary alloy configurations. Using this Magnetic Cluster Expansion <span class="hlt">model</span> Hamiltonian, we perform Monte Carlo simulations and explore magnetic structures of alloys over the entire range of compositions, considering both random and ordered alloy structures. In random alloys, the removal of magnetic collinearity constraint reduces the total magnetic moment but does not affect the predicted range of compositions where the alloys adopt low-temperature ferromagnetic configurations. During alloying of ordered fcc <span class="hlt">Fe</span>-Ni compounds with Cr, chromium atoms tend to replace nickel rathermore » than iron atoms. Replacement of Ni by Cr in ordered alloys with high iron content increases the Curie temperature of the alloys. This can be explained by strong antiferromagnetic <span class="hlt">Fe</span>-Cr coupling, similar to that found in bcc <span class="hlt">Fe</span>-Cr solutions, where the Curie temperature increase, predicted by simulations as a function of Cr concentration, is confirmed by experimental observations. In random alloys, both magnetization and the Curie temperature decrease abruptly with increasing chromium content, in agreement with experiment.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20979418-ferromagnetic-resonance-investigation-prepared-nife-femn-nife-trilayer','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20979418-ferromagnetic-resonance-investigation-prepared-nife-femn-nife-trilayer"><span>Ferromagnetic resonance investigation in as-prepared Ni<span class="hlt">Fe/FeMn/NiFe</span> trilayer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yuan, S. J.; Xu, K.; Yu, L. M.</p> <p>2007-06-01</p> <p>Ni<span class="hlt">Fe/FeMn/NiFe</span> trilayer prepared by dc magnetron sputtering was systematically investigated by ferromagnetic resonance technique (FMR) at room temperature. For Ni<span class="hlt">Fe/FeMn/NiFe</span> trilayer, there are two distinct resonance peaks both in in-plane and out-of-plane FMR spectra, which are attributed to the two Ni<span class="hlt">Fe</span> layers, respectively. The isotropic in-plane resonance field shift is negative for the bottom Ni<span class="hlt">Fe</span> layer, while positive for the top Ni<span class="hlt">Fe</span> layer. And, such phenomena result from the negative interfacial perpendicular anisotropy at the bottom Ni<span class="hlt">Fe/Fe</span>Mn interface and positive interfacial perpendicular anisotropy at the top <span class="hlt">FeMn/NiFe</span> interface. The linewidth of the bottom Ni<span class="hlt">Fe</span> layer is larger than that ofmore » the top Ni<span class="hlt">Fe</span> layer, which might be related to the greater exchange coupling at the bottom Ni<span class="hlt">Fe/Fe</span>Mn interface.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/4141','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/4141"><span><span class="hlt">Validation</span> of urban freeway <span class="hlt">models</span>. [supporting datasets</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>2015-01-01</p> <p>The goal of the SHRP 2 Project L33 <span class="hlt">Validation</span> of Urban Freeway <span class="hlt">Models</span> was to assess and enhance the predictive travel time reliability <span class="hlt">models</span> developed in the SHRP 2 Project L03, Analytic Procedures for Determining the Impacts of Reliability Mitigati...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21609132','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21609132"><span>Developing rural palliative care: <span class="hlt">validating</span> a conceptual <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kelley, Mary Lou; Williams, Allison; DeMiglio, Lily; Mettam, Hilary</p> <p>2011-01-01</p> <p>The purpose of this research was to <span class="hlt">validate</span> a conceptual <span class="hlt">model</span> for developing palliative care in rural communities. This <span class="hlt">model</span> articulates how local rural healthcare providers develop palliative care services according to four sequential phases. The <span class="hlt">model</span> has roots in concepts of community capacity development, evolves from collaborative, generalist rural practice, and utilizes existing health services infrastructure. It addresses how rural providers manage challenges, specifically those related to: lack of resources, minimal community understanding of palliative care, health professionals' resistance, the bureaucracy of the health system, and the obstacles of providing services in rural environments. Seven semi-structured focus groups were conducted with interdisciplinary health providers in 7 rural communities in two Canadian provinces. Using a constant comparative analysis approach, focus group data were analyzed by examining participants' statements in relation to the <span class="hlt">model</span> and comparing emerging themes in the development of rural palliative care to the elements of the <span class="hlt">model</span>. The data <span class="hlt">validated</span> the conceptual <span class="hlt">model</span> as the <span class="hlt">model</span> was able to theoretically predict and explain the experiences of the 7 rural communities that participated in the study. New emerging themes from the data elaborated existing elements in the <span class="hlt">model</span> and informed the requirement for minor revisions. The <span class="hlt">model</span> was <span class="hlt">validated</span> and slightly revised, as suggested by the data. The <span class="hlt">model</span> was confirmed as being a useful theoretical tool for conceptualizing the development of rural palliative care that is applicable in diverse rural communities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009BGeo....6.2041Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009BGeo....6.2041Y"><span>A <span class="hlt">model</span> of <span class="hlt">Fe</span> speciation and biogeochemistry at the Tropical Eastern North Atlantic Time-Series Observatory site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ye, Y.; Völker, C.; Wolf-Gladrow, D. A.</p> <p>2009-10-01</p> <p>A one-dimensional <span class="hlt">model</span> of <span class="hlt">Fe</span> speciation and biogeochemistry, coupled with the General Ocean Turbulence <span class="hlt">Model</span> (GOTM) and a NPZD-type ecosystem <span class="hlt">model</span>, is applied for the Tropical Eastern North Atlantic Time-Series Observatory (TENATSO) site. Among diverse processes affecting <span class="hlt">Fe</span> speciation, this study is focusing on investigating the role of dust particles in removing dissolved iron (DFe) by a more complex description of particle aggregation and sinking, and explaining the abundance of organic <span class="hlt">Fe</span>-binding ligands by <span class="hlt">modelling</span> their origin and fate. The vertical distribution of different particle classes in the <span class="hlt">model</span> shows high sensitivity to changing aggregation rates. Using the aggregation rates from the sensitivity study in this work, <span class="hlt">modelled</span> particle fluxes are close to observations, with dust particles dominating near the surface and aggregates deeper in the water column. POC export at 1000 m is a little higher than regional sediment trap measurements, suggesting further improvement of <span class="hlt">modelling</span> particle aggregation, sinking or remineralisation. <span class="hlt">Modelled</span> strong ligands have a high abundance near the surface and decline rapidly below the deep chlorophyll maximum, showing qualitative similarity to observations. Without production of strong ligands, phytoplankton concentration falls to 0 within the first 2 years in the <span class="hlt">model</span> integration, caused by strong <span class="hlt">Fe</span>-limitation. A nudging of total weak ligands towards a constant value is required for reproducing the observed nutrient-like profiles, assuming a decay time of 7 years for weak ligands. This indicates that weak ligands have a longer decay time and therefore cannot be <span class="hlt">modelled</span> adequately in a one-dimensional <span class="hlt">model</span>. The <span class="hlt">modelled</span> DFe profile is strongly influenced by particle concentration and vertical distribution, because the most important removal of DFe in deeper waters is colloid formation and aggregation. Redissolution of particulate iron is required to reproduce an observed DFe profile at TENATSO site</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28777019','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28777019"><span>Multiple Versus Single Set <span class="hlt">Validation</span> of Multivariate <span class="hlt">Models</span> to Avoid Mistakes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Harrington, Peter de Boves</p> <p>2018-01-02</p> <p><span class="hlt">Validation</span> of multivariate <span class="hlt">models</span> is of current importance for a wide range of chemical applications. Although important, it is neglected. The common practice is to use a single external <span class="hlt">validation</span> set for evaluation. This approach is deficient and may mislead investigators with results that are specific to the single <span class="hlt">validation</span> set of data. In addition, no statistics are available regarding the precision of a derived figure of merit (FOM). A statistical approach using bootstrapped Latin partitions is advocated. This <span class="hlt">validation</span> method makes an efficient use of the data because each object is used once for <span class="hlt">validation</span>. It was reviewed a decade earlier but primarily for the optimization of chemometric <span class="hlt">models</span> this review presents the reasons it should be used for generalized statistical <span class="hlt">validation</span>. Average FOMs with confidence intervals are reported and powerful, matched-sample statistics may be applied for comparing <span class="hlt">models</span> and methods. Examples demonstrate the problems with single <span class="hlt">validation</span> sets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24578582','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24578582"><span>A multiscale MD-<span class="hlt">FE</span> <span class="hlt">model</span> of diffusion in composite media with internal surface interaction based on numerical homogenization procedure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kojic, M; Milosevic, M; Kojic, N; Kim, K; Ferrari, M; Ziemys, A</p> <p>2014-02-01</p> <p>Mass transport by diffusion within composite materials may depend not only on internal microstructural geometry, but also on the chemical interactions between the transported substance and the material of the microstructure. Retrospectively, there is a gap in methods and theory to connect material microstructure properties with macroscale continuum diffusion characteristics. Here we present a new hierarchical multiscale <span class="hlt">model</span> for diffusion within composite materials that couples material microstructural geometry and interactions between diffusing particles and the material matrix. This <span class="hlt">model</span>, which bridges molecular dynamics (MD) and the finite element (<span class="hlt">FE</span>) method, is employed to construct a continuum diffusion <span class="hlt">model</span> based on a novel numerical homogenization procedure. The procedure is general and robust for evaluating constitutive material parameters of the continuum <span class="hlt">model</span>. These parameters include the traditional bulk diffusion coefficients and, additionally, the distances from the solid surface accounting for surface interaction effects. We implemented our <span class="hlt">models</span> to glucose diffusion through the following two geometrical/material configurations: tightly packed silica nanospheres, and a complex fibrous structure surrounding nanospheres. Then, rhodamine 6G diffusion analysis through an aga-rose gel network was performed, followed by a <span class="hlt">model</span> <span class="hlt">validation</span> using our experimental results. The microstructural <span class="hlt">model</span>, numerical homogenization and continuum <span class="hlt">model</span> offer a new platform for <span class="hlt">modeling</span> and predicting mass diffusion through complex biological environment and within composite materials that are used in a wide range of applications, like drug delivery and nanoporous catalysts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=effect+AND+environmental+AND+factors+AND+reproduction&pg=4&id=ED539536','ERIC'); return false;" href="https://eric.ed.gov/?q=effect+AND+environmental+AND+factors+AND+reproduction&pg=4&id=ED539536"><span>Outward Bound Outcome <span class="hlt">Model</span> <span class="hlt">Validation</span> and Multilevel <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Luo, Yuan-Chun</p> <p>2011-01-01</p> <p>This study was intended to measure construct <span class="hlt">validity</span> for the Outward Bound Outcomes Instrument (OBOI) and to predict outcome achievement from individual characteristics and course attributes using multilevel <span class="hlt">modeling</span>. A sample of 2,340 participants was collected by Outward Bound USA between May and September 2009 using the OBOI. Two phases of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110007806','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110007806"><span><span class="hlt">Validation</span> of Community <span class="hlt">Models</span>: Identifying Events in Space Weather <span class="hlt">Model</span> Timelines</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>MacNeice, Peter</p> <p>2009-01-01</p> <p>I develop and document a set of procedures which test the quality of predictions of solar wind speed and polarity of the interplanetary magnetic field (IMF) made by coupled <span class="hlt">models</span> of the ambient solar corona and heliosphere. The Wang-Sheeley-Arge (WSA) <span class="hlt">model</span> is used to illustrate the application of these <span class="hlt">validation</span> procedures. I present an algorithm which detects transitions of the solar wind from slow to high speed. I also present an algorithm which processes the measured polarity of the outward directed component of the IMF. This removes high-frequency variations to expose the longer-scale changes that reflect IMF sector changes. I apply these algorithms to WSA <span class="hlt">model</span> predictions made using a small set of photospheric synoptic magnetograms obtained by the Global Oscillation Network Group as input to the <span class="hlt">model</span>. The results of this preliminary <span class="hlt">validation</span> of the WSA <span class="hlt">model</span> (version 1.6) are summarized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1407805-dislocation-loop-formation-model-fecral-alloys-after-neutron-irradiation-below-dpa','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1407805-dislocation-loop-formation-model-fecral-alloys-after-neutron-irradiation-below-dpa"><span>Dislocation loop formation in <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys after neutron irradiation below 1 dpa</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Field, Kevin G.; Briggs, Samuel A.; Sridharan, Kumar; ...</p> <p>2017-08-01</p> <p><span class="hlt">Fe</span>CrAl alloys with varying compositions and microstructures are under consideration for accident-tolerant fuel cladding, but limited details exist on dislocation loop formation and growth for this class of alloys under neutron irradiation. Four <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys with chromium contents ranging from 10.01 to 17.51 wt % and alunimum contents of 4.78 to 2.93 wt % were neutron irradiated to doses of 0.3–0.8 displacements per atom (dpa) at temperatures of 335–355°C. On-zone STEM imaging revealed a mixed population of black dots and larger dislocation loops with either a/2< 111 > or a< 100 > Burgers vectors. Weak composition dependencies were observedmore » and varied depending on whether the defect size, number density, or ratio of defect types was of interest. Here, the results were found to mirror those of previous studies on <span class="hlt">Fe</span>CrAl and <span class="hlt">Fe</span>Cr alloys irradiated under similar conditions, although distinct differences exist.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JNuM..495...20F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JNuM..495...20F"><span>Dislocation loop formation in <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys after neutron irradiation below 1 dpa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Field, Kevin G.; Briggs, Samuel A.; Sridharan, Kumar; Yamamoto, Yukinori; Howard, Richard H.</p> <p>2017-11-01</p> <p><span class="hlt">Fe</span>CrAl alloys with varying compositions and microstructures are under consideration for accident-tolerant fuel cladding, but limited details exist on dislocation loop formation and growth for this class of alloys under neutron irradiation. Four <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys with chromium contents ranging from 10.01 to 17.51 wt % and aluminum contents of 4.78 to 2.93 wt % were neutron irradiated to doses of 0.3-0.8 displacements per atom (dpa) at temperatures of 335-355 °C. On-zone STEM imaging revealed a mixed population of black dots and larger dislocation loops with either a / 2 〈 111 〉 or a 〈 100 〉 Burgers vectors. Weak composition dependencies were observed and varied depending on whether the defect size, number density, or ratio of defect types was of interest. Results were found to mirror those of previous studies on <span class="hlt">Fe</span>CrAl and <span class="hlt">Fe</span>Cr alloys irradiated under similar conditions, although distinct differences exist.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SSCom.201..120D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SSCom.201..120D"><span>First principles calculations of the magnetic and hyperfine properties of <span class="hlt">Fe/N/Fe</span> and <span class="hlt">Fe/O/Fe</span> multilayers in the ground state of cohesive energy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>dos Santos, A. V.; Samudio Pérez, C. A.; Muenchen, D.; Anibele, T. P.</p> <p>2015-01-01</p> <p>The ground state properties of <span class="hlt">Fe/N/Fe</span> and <span class="hlt">Fe/O/Fe</span> multilayers were investigated using the first principles calculations. The calculations were performed using the Linearized Augmented Plane Wave (LAPW) method implemented in the Wien2k code. A supercell consisting of one layer of nitride (or oxide) between two layers of <span class="hlt">Fe</span> in the bcc structure was used to <span class="hlt">model</span> the structure of the multilayer. The research in new materials also stimulated theoretical and experimental studies of iron-based nitrides due to their variety of structural and magnetic properties for the potential applications as in high strength steels and for high corrosion resistance. It is obvious from many reports that magnetic iron nitrides such as γ-<span class="hlt">Fe</span>4N and α-<span class="hlt">Fe</span>16N2 have interesting magnetic properties, among these a high magnetisation saturation and a high density crimp. However, although <span class="hlt">Fe</span>-N films and multilayers have many potential applications, they can be produced in many ways and are being extensively studied from the theoretical point of view there is no detailed knowledge of their electronic structure. Clearly, efforts to understand the influence of the nitrogen atoms on the entire electronic structure are needed as to correctly interpret the observed changes in the magnetic properties when going from <span class="hlt">Fe</span>-N bulk compounds to multilayer structures. Nevertheless, the N atoms are not solely responsible for electronics alterations in solid compounds. Theoretical results showed that <span class="hlt">Fe</span>4X bulk compounds, where X is a variable atom with increasing atomic number (Z), the nature of bonding between X and adjacent <span class="hlt">Fe</span> atoms changes from more covalent to more ionic and the magnetic moments of <span class="hlt">Fe</span> also increase for Z=7, i.e. N. This is an indicative that atoms with a Z number higher than 7, i.e., O, can produce several new alterations in the entire magnetic properties of <span class="hlt">Fe</span> multilayers. This paper presents the first results of an ab-initio electronic structure calculations, performed for <span class="hlt">Fe</span>-N and <span class="hlt">Fe</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA425090','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA425090"><span><span class="hlt">Validating</span> Computational Human Behavior <span class="hlt">Models</span>: Consistency and Accuracy Issues</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2004-06-01</p> <p>includes a discussion of SME demographics, content, and organization of the datasets . This research generalizes data from two pilot studies and two base...meet requirements for <span class="hlt">validating</span> the varied and complex behavioral <span class="hlt">models</span>. Through a series of empirical studies , this research identifies subject...meet requirements for <span class="hlt">validating</span> the varied and complex behavioral <span class="hlt">models</span>. Through a series of empirical studies , this research identifies subject</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25461840','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25461840"><span>[<span class="hlt">FeFe</span>]- and [Ni<span class="hlt">Fe</span>]-hydrogenase diversity, mechanism, and maturation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peters, John W; Schut, Gerrit J; Boyd, Eric S; Mulder, David W; Shepard, Eric M; Broderick, Joan B; King, Paul W; Adams, Michael W W</p> <p>2015-06-01</p> <p>The [<span class="hlt">FeFe</span>]- and [Ni<span class="hlt">Fe</span>]-hydrogenases catalyze the formal interconversion between hydrogen and protons and electrons, possess characteristic non-protein ligands at their catalytic sites and thus share common mechanistic features. Despite the similarities between these two types of hydrogenases, they clearly have distinct evolutionary origins and likely emerged from different selective pressures. [<span class="hlt">FeFe</span>]-hydrogenases are widely distributed in fermentative anaerobic microorganisms and likely evolved under selective pressure to couple hydrogen production to the recycling of electron carriers that accumulate during anaerobic metabolism. In contrast, many [Ni<span class="hlt">Fe</span>]-hydrogenases catalyze hydrogen oxidation as part of energy metabolism and were likely key enzymes in early life and arguably represent the predecessors of modern respiratory metabolism. Although the reversible combination of protons and electrons to generate hydrogen gas is the simplest of chemical reactions, the [<span class="hlt">FeFe</span>]- and [Ni<span class="hlt">Fe</span>]-hydrogenases have distinct mechanisms and differ in the fundamental chemistry associated with proton transfer and control of electron flow that also help to define catalytic bias. A unifying feature of these enzymes is that hydrogen activation itself has been restricted to one solution involving diatomic ligands (carbon monoxide and cyanide) bound to an <span class="hlt">Fe</span> ion. On the other hand, and quite remarkably, the biosynthetic mechanisms to produce these ligands are exclusive to each type of enzyme. Furthermore, these mechanisms represent two independent solutions to the formation of complex bioinorganic active sites for catalyzing the simplest of chemical reactions, reversible hydrogen oxidation. As such, the [<span class="hlt">FeFe</span>]- and [Ni<span class="hlt">Fe</span>]-hydrogenases are arguably the most profound case of convergent evolution. This article is part of a Special Issue entitled: <span class="hlt">Fe</span>/S proteins: Analysis, structure, function, biogenesis and diseases. Copyright © 2014 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008A%26A...477..543G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008A%26A...477..543G"><span>Physical conditions in Ca<span class="hlt">Fe</span> interstellar clouds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gnaciński, P.; Krogulec, M.</p> <p>2008-01-01</p> <p>Interstellar clouds that exhibit strong Ca I and <span class="hlt">Fe</span> I lines are called Ca<span class="hlt">Fe</span> clouds. Ionisation equilibrium equations were used to <span class="hlt">model</span> the column densities of Ca II, Ca I, K I, Na I, <span class="hlt">Fe</span> I and Ti II in Ca<span class="hlt">Fe</span> clouds. We find that the chemical composition of Ca<span class="hlt">Fe</span> clouds is solar and that there is no depletion into dust grains. Ca<span class="hlt">Fe</span> clouds have high electron densities, n_e≈1 cm-3, that lead to high column densities of neutral Ca and <span class="hlt">Fe</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=emotional+AND+stability+AND+teachers&pg=5&id=EJ689717','ERIC'); return false;" href="https://eric.ed.gov/?q=emotional+AND+stability+AND+teachers&pg=5&id=EJ689717"><span>Adolescent Personality: A Five-Factor <span class="hlt">Model</span> Construct <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Baker, Spencer T.; Victor, James B.; Chambers, Anthony L.; Halverson, Jr., Charles F.</p> <p>2004-01-01</p> <p>The purpose of this study was to investigate convergent and discriminant <span class="hlt">validity</span> of the five-factor <span class="hlt">model</span> of adolescent personality in a school setting using three different raters (methods): self-ratings, peer ratings, and teacher ratings. The authors investigated <span class="hlt">validity</span> through a multitrait-multimethod matrix and a confirmatory factor…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930061398&hterms=model+atomic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmodel%2Batomic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930061398&hterms=model+atomic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmodel%2Batomic"><span>Atomic data for a five-configuration <span class="hlt">model</span> of <span class="hlt">Fe</span> XIV</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bhatia, A. K.; Kastner, S. O.</p> <p>1993-01-01</p> <p>Collision strengths calculated in the distorted wave approximation are presented for electron excitation of <span class="hlt">Fe</span> XIV at incident energies of 10, 20 and 30 Rydbergs. Configurations 3s(2)3p, 3s3p(2), 3s(2)3d, 3p(3), and 3s3p3d are included, comprising 40 levels, and wave function mixing coefficients are tabulated. Radiative transition rates are given for the same <span class="hlt">model</span> using the Superstructure program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED065591.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED065591.pdf"><span>A <span class="hlt">Model</span> for Estimating the Reliability and <span class="hlt">Validity</span> of Criterion-Referenced Measures.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Edmonston, Leon P.; Randall, Robert S.</p> <p></p> <p>A decision <span class="hlt">model</span> designed to determine the reliability and <span class="hlt">validity</span> of criterion referenced measures (CRMs) is presented. General procedures which pertain to the <span class="hlt">model</span> are discussed as to: Measures of relationship, Reliability, <span class="hlt">Validity</span> (content, criterion-oriented, and construct <span class="hlt">validation</span>), and Item Analysis. The decision <span class="hlt">model</span> is presented in…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23001032','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23001032"><span>The catalytic center of ferritin regulates iron storage via <span class="hlt">Fe(II)-Fe</span>(III) displacement.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Honarmand Ebrahimi, Kourosh; Bill, Eckhard; Hagedoorn, Peter-Leon; Hagen, Wilfred R</p> <p>2012-11-01</p> <p>A conserved iron-binding site, the ferroxidase center, regulates the vital iron storage role of the ubiquitous protein ferritin in iron metabolism. It is commonly thought that two <span class="hlt">Fe</span>(II) simultaneously bind the ferroxidase center and that the oxidized <span class="hlt">Fe(III)-O(H)-Fe</span>(III) product spontaneously enters the cavity of ferritin as a unit. In contrast, in some bacterioferritins and in archaeal ferritins a persistent di-iron prosthetic group in this center is believed to mediate catalysis of core formation. Using a combination of binding experiments and isotopically labeled (57)<span class="hlt">Fe</span>(II), we studied two systems in comparison: the ferritin from the hyperthermophilic archaeal anaerobe Pyrococcus furiosus (PfFtn) and the eukaryotic human H ferritin (HuHF). The results do not support either of the two paradigmatic <span class="hlt">models</span>; instead they suggest a unifying mechanism in which the <span class="hlt">Fe(III)-O-Fe</span>(III) unit resides in the ferroxidase center until it is sequentially displaced by <span class="hlt">Fe</span>(II).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1350922-combined-apt-sans-investigation-phase-precipitation-neutron-irradiated-model-fecral-alloys','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1350922-combined-apt-sans-investigation-phase-precipitation-neutron-irradiated-model-fecral-alloys"><span>A combined APT and SANS investigation of α' phase precipitation in neutron-irradiated <span class="hlt">model</span> <span class="hlt">Fe</span>CrAl alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Briggs, Samuel A.; Edmondson, Philip D.; Littrell, Kenneth C.; ...</p> <p>2017-03-01</p> <p>Here, <span class="hlt">Fe</span>CrAl alloys are currently under consideration for accident-tolerant fuel cladding applications in light water reactors owing to their superior high-temperature oxidation and corrosion resistance compared to the Zr-based alloys currently employed. However, their performance could be limited by precipitation of a Cr-rich α' phase that tends to embrittle high-Cr ferritic <span class="hlt">Fe</span>-based alloys. In this study, four <span class="hlt">Fe</span>CrAl <span class="hlt">model</span> alloys with 10–18 at.% Cr and 5.8–9.3 at.% Al were neutron-irradiated to nominal damage doses up to 7.0 displacements per atom at a target temperature of 320 °C. Small angle neutron scattering techniques were coupled with atom probe tomography to assessmore » the composition and morphology of the resulting α' precipitates. It was demonstrated that Al additions partially destabilize the α' phase, generally resulting in precipitates with lower Cr contents when compared with binary <span class="hlt">Fe</span>-Cr systems. The precipitate morphology evolution with dose exhibited a transient coarsening regime akin to previously observed behavior in aged <span class="hlt">Fe</span>-Cr alloys. Similar behavior to predictions of the LSW/UOKV <span class="hlt">models</span> suggests that α' precipitation in irradiated <span class="hlt">Fe</span>CrAl is a diffusion-limited process with coarsening mechanisms similar to those in thermally aged high-Cr ferritic alloys.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LNCS.5693..139M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LNCS.5693..139M"><span>Refinement, <span class="hlt">Validation</span> and Benchmarking of a <span class="hlt">Model</span> for E-Government Service Quality</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Magoutas, Babis; Mentzas, Gregoris</p> <p></p> <p>This paper presents the refinement and <span class="hlt">validation</span> of a <span class="hlt">model</span> for Quality of e-Government Services (QeGS). We built upon our previous work where a conceptualized <span class="hlt">model</span> was identified and put focus on the confirmatory phase of the <span class="hlt">model</span> development process, in order to come up with a <span class="hlt">valid</span> and reliable QeGS <span class="hlt">model</span>. The <span class="hlt">validated</span> <span class="hlt">model</span>, which was benchmarked with very positive results with similar <span class="hlt">models</span> found in the literature, can be used for measuring the QeGS in a reliable and <span class="hlt">valid</span> manner. This will form the basis for a continuous quality improvement process, unleashing the full potential of e-government services for both citizens and public administrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=241951','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=241951"><span>Purified glycosaminoglycans from cooked haddock may enhance <span class="hlt">Fe</span> uptake via endocytosis in a Caco-2 cell culture <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>This study aims to understand the enhancing effect of glycosaminoglycans (GAGs), such as chondroitin/dermatan structures, on <span class="hlt">Fe</span> uptake to Caco-2 cells. High sulfated GAGs were selectively purified from cooked haddock. An in vitro digestion/Caco-2 cell culture <span class="hlt">model</span> was used to evaluate <span class="hlt">Fe</span> uptake (ce...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1235644','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1235644"><span>SPR Hydrostatic Column <span class="hlt">Model</span> Verification and <span class="hlt">Validation</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bettin, Giorgia; Lord, David; Rudeen, David Keith</p> <p>2015-10-01</p> <p>A Hydrostatic Column <span class="hlt">Model</span> (HCM) was developed to help differentiate between normal "tight" well behavior and small-leak behavior under nitrogen for testing the pressure integrity of crude oil storage wells at the U.S. Strategic Petroleum Reserve. This effort was motivated by steady, yet distinct, pressure behavior of a series of Big Hill caverns that have been placed under nitrogen for extended period of time. This report describes the HCM <span class="hlt">model</span>, its functional requirements, the <span class="hlt">model</span> structure and the verification and <span class="hlt">validation</span> process. Different modes of operation are also described, which illustrate how the software can be used to <span class="hlt">model</span> extendedmore » nitrogen monitoring and Mechanical Integrity Tests by predicting wellhead pressures along with nitrogen interface movements. <span class="hlt">Model</span> verification has shown that the program runs correctly and it is implemented as intended. The cavern BH101 long term nitrogen test was used to <span class="hlt">validate</span> the <span class="hlt">model</span> which showed very good agreement with measured data. This supports the claim that the <span class="hlt">model</span> is, in fact, capturing the relevant physical phenomena and can be used to make accurate predictions of both wellhead pressure and interface movements.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=definition+AND+validity+AND+reliability&pg=4&id=EJ542065','ERIC'); return false;" href="https://eric.ed.gov/?q=definition+AND+validity+AND+reliability&pg=4&id=EJ542065"><span>Longitudinal <span class="hlt">Models</span> of Reliability and <span class="hlt">Validity</span>: A Latent Curve Approach.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Tisak, John; Tisak, Marie S.</p> <p>1996-01-01</p> <p>Dynamic generalizations of reliability and <span class="hlt">validity</span> that will incorporate longitudinal or developmental <span class="hlt">models</span>, using latent curve analysis, are discussed. A latent curve <span class="hlt">model</span> formulated to depict change is incorporated into the classical definitions of reliability and <span class="hlt">validity</span>. The approach is illustrated with sociological and psychological…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22695987','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22695987"><span>A finite element <span class="hlt">model</span> of the foot and ankle for automotive impact applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shin, Jaeho; Yue, Neng; Untaroiu, Costin D</p> <p>2012-12-01</p> <p>A finite element (<span class="hlt">FE</span>) <span class="hlt">model</span> of the foot and leg was developed to improve understanding of injury mechanisms of the ankle and subtalar joints during vehicle collisions and to aid in the design of injury countermeasures. The <span class="hlt">FE</span> <span class="hlt">model</span> was developed based on the reconstructed geometry of a male volunteer close to the anthropometry of a 50th percentile male and a commercial anatomical database. While the forefoot bones were defined as rigid bodies connected by ligament <span class="hlt">models</span>, the surrounding bones of the ankle and subtalar joints and the leg bones were <span class="hlt">modeled</span> as deformable structures. The material and structural properties were selected based on a synthesis of current knowledge of the constitutive <span class="hlt">models</span> for each tissue. The whole foot and leg <span class="hlt">model</span> was <span class="hlt">validated</span> in different loading conditions including forefoot impact, axial rotation, dorsiflexion, and combined loadings. Overall results obtained in the <span class="hlt">model</span> <span class="hlt">validation</span> indicated improved biofidelity relative to previous <span class="hlt">FE</span> <span class="hlt">models</span>. The developed <span class="hlt">model</span> was used to investigate the injury tolerance of the ankle joint under brake pedal loading for internally and externally rotated feet. Ligament failures were predicted as the main source of injury in this loading condition. A 12% variation of failure moment was observed in the range of axial foot rotations (±15°). The most vulnerable position was the internally rotated (15°) posture among three different foot positions. Furthermore, the present foot and ankle <span class="hlt">model</span> will be coupled together with other body region <span class="hlt">FE</span> <span class="hlt">models</span> into the state-of-art human <span class="hlt">FE</span> <span class="hlt">model</span> to be used in the field of automotive safety.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20487188','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20487188"><span>Development and <span class="hlt">validation</span> of a mass casualty conceptual <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Culley, Joan M; Effken, Judith A</p> <p>2010-03-01</p> <p>To develop and <span class="hlt">validate</span> a conceptual <span class="hlt">model</span> that provides a framework for the development and evaluation of information systems for mass casualty events. The <span class="hlt">model</span> was designed based on extant literature and existing theoretical <span class="hlt">models</span>. A purposeful sample of 18 experts <span class="hlt">validated</span> the <span class="hlt">model</span>. Open-ended questions, as well as a 7-point Likert scale, were used to measure expert consensus on the importance of each construct and its relationship in the <span class="hlt">model</span> and the usefulness of the <span class="hlt">model</span> to future research. Computer-mediated applications were used to facilitate a modified Delphi technique through which a panel of experts provided <span class="hlt">validation</span> for the conceptual <span class="hlt">model</span>. Rounds of questions continued until consensus was reached, as measured by an interquartile range (no more than 1 scale point for each item); stability (change in the distribution of responses less than 15% between rounds); and percent agreement (70% or greater) for indicator questions. Two rounds of the Delphi process were needed to satisfy the criteria for consensus or stability related to the constructs, relationships, and indicators in the <span class="hlt">model</span>. The panel reached consensus or sufficient stability to retain all 10 constructs, 9 relationships, and 39 of 44 indicators. Experts viewed the <span class="hlt">model</span> as useful (mean of 5.3 on a 7-point scale). <span class="hlt">Validation</span> of the <span class="hlt">model</span> provides the first step in understanding the context in which mass casualty events take place and identifying variables that impact outcomes of care. This study provides a foundation for understanding the complexity of mass casualty care, the roles that nurses play in mass casualty events, and factors that must be considered in designing and evaluating information-communication systems to support effective triage under these conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001SPIE.4582...95W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001SPIE.4582...95W"><span><span class="hlt">Modeling</span> of optical mirror and electromechanical behavior</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Fang; Lu, Chao; Liu, Zishun; Liu, Ai Q.; Zhang, Xu M.</p> <p>2001-10-01</p> <p>This paper presents finite element (<span class="hlt">FE</span>) simulation and theoretical analysis of novel MEMS fiber-optical switches actuated by electrostatic attraction. <span class="hlt">FE</span> simulation for the switches under static and dynamic loading are first carried out to reveal the mechanical characteristics of the minimum or critical switching voltages, the natural frequencies, mode shapes and response under different levels of electrostatic attraction load. To <span class="hlt">validate</span> the <span class="hlt">FE</span> simulation results, a theoretical (or analytical) <span class="hlt">model</span> is then developed for one specific switch, i.e., Plate_40_104. Good agreement is found between the <span class="hlt">FE</span> simulation and the analytical results. From both <span class="hlt">FE</span> simulation and theoretical analysis, the critical switching voltage for Plate_40_104 is derived to be 238 V for the switching angel of 12 degree(s). The critical switching on and off times are 431 microsecond(s) and 67 microsecond(s) , respectively. The present study not only develops good <span class="hlt">FE</span> and analytical <span class="hlt">models</span>, but also demonstrates step by step a method to simplify a real optical switch structure with reference to the <span class="hlt">FE</span> simulation results for analytical purpose. With the <span class="hlt">FE</span> and analytical <span class="hlt">models</span>, it is easy to obtain any information about the mechanical behaviors of the optical switches, which are helpful in yielding optimized design.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013aero.confE.102K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013aero.confE.102K"><span><span class="hlt">Model</span>-based verification and <span class="hlt">validation</span> of the SMAP uplink processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khan, M. O.; Dubos, G. F.; Tirona, J.; Standley, S.</p> <p></p> <p><span class="hlt">Model</span>-Based Systems Engineering (MBSE) is being used increasingly within the spacecraft design community because of its benefits when compared to document-based approaches. As the complexity of projects expands dramatically with continually increasing computational power and technology infusion, the time and effort needed for verification and <span class="hlt">validation</span> (V& V) increases geometrically. Using simulation to perform design <span class="hlt">validation</span> with system-level <span class="hlt">models</span> earlier in the life cycle stands to bridge the gap between design of the system (based on system-level requirements) and verifying those requirements/<span class="hlt">validating</span> the system as a whole. This case study stands as an example of how a project can <span class="hlt">validate</span> a system-level design earlier in the project life cycle than traditional V& V processes by using simulation on a system <span class="hlt">model</span>. Specifically, this paper describes how simulation was added to a system <span class="hlt">model</span> of the Soil Moisture Active-Passive (SMAP) mission's uplink process. Also discussed are the advantages and disadvantages of the methods employed and the lessons learned; which are intended to benefit future <span class="hlt">model</span>-based and simulation-based development efforts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986PCM....13...31W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986PCM....13...31W"><span>X-ray K-edge absorption spectra of <span class="hlt">Fe</span> minerals and <span class="hlt">model</span> compounds: II. EXAFS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Waychunas, Glenn A.; Brown, Gordon E.; Apted, Michael J.</p> <p>1986-01-01</p> <p>K-edge extended X-ray absorption fine structure (EXAFS) spectra of <span class="hlt">Fe</span> in varying environments in a suite of well-characterized silicate and oxide minerals were collected using synchrotron radiation and analyzed using single scattering approximation theory to yield nearest neighbor <span class="hlt">Fe</span>-O distances and coordination numbers. The partial inverse character of synthetic hercynite spinal was verified in this way. Comparison of the results from all samples with structural data from X-ray diffraction crystal structure refinements indicates that EXAFS-derived first neighbor distances are generally accurate to ±0.02 Å using only theoretically generated phase information, and may be improved over this if similar <span class="hlt">model</span> compounds are used to determine EXAFS phase functions. Coordination numbers are accurate to ±20 percent and can be similarly improved using <span class="hlt">model</span> compound EXAFS amplitude information. However, in particular cases the EXAFS-derived distances may be shortened, and the coordination number reduced, by the effects of static and thermal disorder or by partial overlap of the longer <span class="hlt">Fe</span>-O first neighbor distances with second neighbor distances in the EXAFS structure function. In the former case the total information available in the EXAFS is limited by the disorder, while in the latter case more accurate results can in principle be obtained by multiple neighbor EXAFS analysis. The EXAFS and XANES spectra of <span class="hlt">Fe</span> in Nain, Labrador osumulite and Lakeview, Oregon plagioclase are also analyzed as an example of the application of X-ray absorption spectroscopy to metal ion site occupation determination in minerals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CoMP..173...20U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CoMP..173...20U"><span>Behaviour of <span class="hlt">Fe</span>4O5-Mg2<span class="hlt">Fe</span>2O5 solid solutions and their relation to coexisting Mg-<span class="hlt">Fe</span> silicates and oxide phases</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Uenver-Thiele, Laura; Woodland, Alan B.; Miyajima, Nobuyoshi; Ballaran, Tiziana Boffa; Frost, Daniel J.</p> <p>2018-03-01</p> <p>Experiments at high pressures and temperatures were carried out (1) to investigate the crystal-chemical behaviour of <span class="hlt">Fe</span>4O5-Mg2<span class="hlt">Fe</span>2O5 solid solutions and (2) to explore the phase relations involving (Mg,<span class="hlt">Fe</span>)2<span class="hlt">Fe</span>2O5 (denoted as O5-phase) and Mg-<span class="hlt">Fe</span> silicates. Multi-anvil experiments were performed at 11-20 GPa and 1100-1600 °C using different starting compositions including two that were Si-bearing. In Si-free experiments the O5-phase coexists with <span class="hlt">Fe</span>2O3, hp-(Mg,<span class="hlt">Fe)Fe</span>2O4, (Mg,<span class="hlt">Fe</span>)3<span class="hlt">Fe</span>4O9 or an unquenchable phase of different stoichiometry. Si-bearing experiments yielded phase assemblages consisting of the O5-phase together with olivine, wadsleyite or ringwoodite, majoritic garnet or <span class="hlt">Fe</span>3+-bearing phase B. However, (Mg,<span class="hlt">Fe</span>)2<span class="hlt">Fe</span>2O5 does not incorporate Si. Electron microprobe analyses revealed that phase B incorporates significant amounts of <span class="hlt">Fe</span>2+ and <span class="hlt">Fe</span>3+ (at least 1.0 cations <span class="hlt">Fe</span> per formula unit). <span class="hlt">Fe</span>-L2,3-edge energy-loss near-edge structure spectra confirm the presence of ferric iron [<span class="hlt">Fe</span>3+/Fetot = 0.41(4)] and indicate substitution according to the following charge-balanced exchange: [4]Si4+ + [6]Mg2+ = 2<span class="hlt">Fe</span>3+. The ability to accommodate <span class="hlt">Fe</span>2+ and <span class="hlt">Fe</span>3+ makes this potential "water-storing" mineral interesting since such substitutions should enlarge its stability field. The thermodynamic properties of Mg2<span class="hlt">Fe</span>2O5 have been refined, yielding H°1bar,298 = - 1981.5 kJ mol- 1. Solid solution is complete across the <span class="hlt">Fe</span>4O5-Mg2<span class="hlt">Fe</span>2O5 binary. Molar volume decreases essentially linearly with increasing Mg content, consistent with ideal mixing behaviour. The partitioning of Mg and <span class="hlt">Fe</span>2+ with silicates indicates that (Mg,<span class="hlt">Fe</span>)2<span class="hlt">Fe</span>2O5 has a strong preference for <span class="hlt">Fe</span>2+. <span class="hlt">Modelling</span> of partitioning with olivine is consistent with the O5-phase exhibiting ideal mixing behaviour. Mg-<span class="hlt">Fe</span>2+ partitioning between (Mg,<span class="hlt">Fe</span>)2<span class="hlt">Fe</span>2O5 and ringwoodite or wadsleyite is influenced by the presence of <span class="hlt">Fe</span>3+ and OH incorporation in the silicate phases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B31E2035N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B31E2035N"><span>A subsurface <span class="hlt">Fe</span>-silicate weathering microbiome</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Napieralski, S. A.; Buss, H. L.; Roden, E. E.</p> <p>2017-12-01</p> <p>Traditional <span class="hlt">models</span> of microbially mediated weathering of primary <span class="hlt">Fe</span>-bearing minerals often invoke organic ligands (e.g. siderophores) used for nutrient acquisition. However, it is well known that the oxidation of <span class="hlt">Fe</span>(II) governs the overall rate of <span class="hlt">Fe</span>-silicate mineral dissolution. Recent work has demonstrated the ability of lithtrophic iron oxidizing bacteria (<span class="hlt">Fe</span>OB) to grow via the oxidation of structural <span class="hlt">Fe</span>(II) in biotite as a source of metabolic energy with evidence suggesting a direct enzymatic attack on the mineral surface. This process necessitates the involvement of dedicated outer membrane proteins that interact with insoluble mineral phases in a process known as extracellular electron transfer (EET). To investigate the potential role <span class="hlt">Fe</span>OB in a terrestrial subsurface weathering system, samples were obtained from the bedrock-saprolite interface (785 cm depth) within the Rio Icacos Watershed of the Luquillo Mountains in Puerto Rico. Prior geochemical evidence suggests the flux of <span class="hlt">Fe</span>(II) from the weathering bedrock supports a robust lithotrophic microbial community at depth. Current work confirms the activity of microorganism in situ, with a marked increase in ATP near the bedrock-saprolite interface. Regolith recovered from the interface was used as inoculum to establish enrichment cultures with powderized <span class="hlt">Fe</span>(II)-bearing minerals serving as the sole energy source. Monitoring of the <span class="hlt">Fe(II)/Fe</span>(total) ratio and ATP generation suggests growth of microorganisms coupled to the oxidation of mineral bound <span class="hlt">Fe</span>(II). Analysis of 16S rRNA gene and shotgun metagenomic libraries from in situ and enrichment culture samples lends further support to <span class="hlt">Fe</span>OB involvement in the weathering process. Multiple metagenomic bins related to known <span class="hlt">Fe</span>OB, including Betaproteobacteria genera, contain homologs to <span class="hlt">model</span> EET systems, including Cyc2 and MtoAB. Our approach combining geochemistry and metagenomics with ongoing microbiological and genomic characterization of novel isolates obtained</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020076391','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020076391"><span>Control Oriented <span class="hlt">Modeling</span> and <span class="hlt">Validation</span> of Aeroservoelastic Systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crowder, Marianne; deCallafon, Raymond (Principal Investigator)</p> <p>2002-01-01</p> <p>Lightweight aircraft design emphasizes the reduction of structural weight to maximize aircraft efficiency and agility at the cost of increasing the likelihood of structural dynamic instabilities. To ensure flight safety, extensive flight testing and active structural servo control strategies are required to explore and expand the boundary of the flight envelope. Aeroservoelastic (ASE) <span class="hlt">models</span> can provide online flight monitoring of dynamic instabilities to reduce flight time testing and increase flight safety. The success of ASE <span class="hlt">models</span> is determined by the ability to take into account varying flight conditions and the possibility to perform flight monitoring under the presence of active structural servo control strategies. In this continued study, these aspects are addressed by developing specific methodologies and algorithms for control relevant robust identification and <span class="hlt">model</span> <span class="hlt">validation</span> of aeroservoelastic structures. The closed-loop <span class="hlt">model</span> robust identification and <span class="hlt">model</span> <span class="hlt">validation</span> are based on a fractional <span class="hlt">model</span> approach where the <span class="hlt">model</span> uncertainties are characterized in a closed-loop relevant way.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMMR21A1986G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMMR21A1986G"><span>The Partial Molar Volume and Compressibility of the <span class="hlt">Fe</span>O Component in <span class="hlt">Model</span> Basalts (Mixed CaAl2Si2O8-CaMgSi2O6-Ca<span class="hlt">Fe</span>Si2O6 Liquids) at 0 GPa: evidence of <span class="hlt">Fe</span>2+ in 6-fold coordination</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, X.; Lange, R. A.; Ai, Y.</p> <p>2010-12-01</p> <p><span class="hlt">Fe</span>O is an important component in magmatic liquids and yet its partial molar volume at one bar is not as well known as that for <span class="hlt">Fe</span>2O3 because of the difficulty of performing double-bob density measurements under reducing conditions. Moreover, there is growing evidence from spectroscopic studies that <span class="hlt">Fe</span>2+ occurs in 4, 5, and 6-fold coordination in silicate melts, and it is expected that the partial molar volume and compressibility of the <span class="hlt">Fe</span>O component will vary accordingly. We have conducted both density and relaxed sound speed measurements on four liquids in the An-Di-Hd (CaAl2Si2O8-CaMgSi2O6-Ca<span class="hlt">Fe</span>Si2O6) system: (1) Di-Hd (50:50), (2) An-Hd (50:50), (3) An-Di-Hd (33:33:33) and (4) Hd (100). Densities were measured between 1573 and 1838 K at one bar with the double-bob Archimedean method using molybdenum bobs and crucibles in a reducing gas (1%CO-99%Ar) environment. The sound speeds were measured under similar conditions with a frequency-sweep acoustic interferometer, and used to calculate isothermal compressibility. All the density data for the three multi-component (<span class="hlt">model</span> basalt) liquids were combined with density data on SiO2-Al2O3-CaO-MgO-K2O-Na2O liquids (Lange, 1997) in a fit to a linear volume equation; the results lead to a partial molar volume (±1σ) for <span class="hlt">Fe</span>O =11.7 ± 0.3(±1σ) cm3/mol at 1723 K. This value is similar to that for crystalline <span class="hlt">Fe</span>O at 298 K (halite structure; 12.06 cm3/mol), which suggests an average <span class="hlt">Fe</span>2+ coordination of ~6 in these <span class="hlt">model</span> basalt compositions. In contrast, the fitted partial molar volume of <span class="hlt">Fe</span>O in pure hedenbergite liquid is 14.6 ± 0.3 at 1723 K, which is consistent with an average <span class="hlt">Fe</span>2+ coordination of 4.3 derived from EXAFS spectroscopy (Rossano, 2000). Similarly, all the compressibility data for the three multi-component liquids were combined with compressibility data on SiO2-Al2O3-CaO-MgO liquids (Ai and Lange, 2008) in a fit to an ideal mixing <span class="hlt">model</span> for melt compressibility; the results lead to a partial molar</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017FrP.....5...61J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017FrP.....5...61J"><span>Design and <span class="hlt">validation</span> of diffusion MRI <span class="hlt">models</span> of white matter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jelescu, Ileana O.; Budde, Matthew D.</p> <p>2017-11-01</p> <p>Diffusion MRI is arguably the method of choice for characterizing white matter microstructure in vivo. Over the typical duration of diffusion encoding, the displacement of water molecules is conveniently on a length scale similar to that of the underlying cellular structures. Moreover, water molecules in white matter are largely compartmentalized which enables biologically-inspired compartmental diffusion <span class="hlt">models</span> to characterize and quantify the true biological microstructure. A plethora of white matter <span class="hlt">models</span> have been proposed. However, overparameterization and mathematical fitting complications encourage the introduction of simplifying assumptions that vary between different approaches. These choices impact the quantitative estimation of <span class="hlt">model</span> parameters with potential detriments to their biological accuracy and promised specificity. First, we review biophysical white matter <span class="hlt">models</span> in use and recapitulate their underlying assumptions and realms of applicability. Second, we present up-to-date efforts to <span class="hlt">validate</span> parameters estimated from biophysical <span class="hlt">models</span>. Simulations and dedicated phantoms are useful in assessing the performance of <span class="hlt">models</span> when the ground truth is known. However, the biggest challenge remains the <span class="hlt">validation</span> of the “biological accuracy” of estimated parameters. Complementary techniques such as microscopy of fixed tissue specimens have facilitated direct comparisons of estimates of white matter fiber orientation and densities. However, <span class="hlt">validation</span> of compartmental diffusivities remains challenging, and complementary MRI-based techniques such as alternative diffusion encodings, compartment-specific contrast agents and metabolites have been used to <span class="hlt">validate</span> diffusion <span class="hlt">models</span>. Finally, white matter injury and disease pose additional challenges to <span class="hlt">modeling</span>, which are also discussed. This review aims to provide an overview of the current state of <span class="hlt">models</span> and their <span class="hlt">validation</span> and to stimulate further research in the field to solve the remaining open</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5947881','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5947881"><span>Design and <span class="hlt">validation</span> of diffusion MRI <span class="hlt">models</span> of white matter</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jelescu, Ileana O.; Budde, Matthew D.</p> <p>2018-01-01</p> <p>Diffusion MRI is arguably the method of choice for characterizing white matter microstructure in vivo. Over the typical duration of diffusion encoding, the displacement of water molecules is conveniently on a length scale similar to that of the underlying cellular structures. Moreover, water molecules in white matter are largely compartmentalized which enables biologically-inspired compartmental diffusion <span class="hlt">models</span> to characterize and quantify the true biological microstructure. A plethora of white matter <span class="hlt">models</span> have been proposed. However, overparameterization and mathematical fitting complications encourage the introduction of simplifying assumptions that vary between different approaches. These choices impact the quantitative estimation of <span class="hlt">model</span> parameters with potential detriments to their biological accuracy and promised specificity. First, we review biophysical white matter <span class="hlt">models</span> in use and recapitulate their underlying assumptions and realms of applicability. Second, we present up-to-date efforts to <span class="hlt">validate</span> parameters estimated from biophysical <span class="hlt">models</span>. Simulations and dedicated phantoms are useful in assessing the performance of <span class="hlt">models</span> when the ground truth is known. However, the biggest challenge remains the <span class="hlt">validation</span> of the “biological accuracy” of estimated parameters. Complementary techniques such as microscopy of fixed tissue specimens have facilitated direct comparisons of estimates of white matter fiber orientation and densities. However, <span class="hlt">validation</span> of compartmental diffusivities remains challenging, and complementary MRI-based techniques such as alternative diffusion encodings, compartment-specific contrast agents and metabolites have been used to <span class="hlt">validate</span> diffusion <span class="hlt">models</span>. Finally, white matter injury and disease pose additional challenges to <span class="hlt">modeling</span>, which are also discussed. This review aims to provide an overview of the current state of <span class="hlt">models</span> and their <span class="hlt">validation</span> and to stimulate further research in the field to solve the remaining open</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171634','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171634"><span>The Role of Structural <span class="hlt">Models</span> in the Solar Sail Flight <span class="hlt">Validation</span> Process</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Johnston, John D.</p> <p>2004-01-01</p> <p>NASA is currently soliciting proposals via the New Millennium Program ST-9 opportunity for a potential Solar Sail Flight <span class="hlt">Validation</span> (SSFV) experiment to develop and operate in space a deployable solar sail that can be steered and provides measurable acceleration. The approach planned for this experiment is to test and <span class="hlt">validate</span> <span class="hlt">models</span> and processes for solar sail design, fabrication, deployment, and flight. These <span class="hlt">models</span> and processes would then be used to design, fabricate, and operate scaleable solar sails for future space science missions. There are six <span class="hlt">validation</span> objectives planned for the ST9 SSFV experiment: 1) <span class="hlt">Validate</span> solar sail design tools and fabrication methods; 2) <span class="hlt">Validate</span> controlled deployment; 3) <span class="hlt">Validate</span> in space structural characteristics (focus of poster); 4) <span class="hlt">Validate</span> solar sail attitude control; 5) <span class="hlt">Validate</span> solar sail thrust performance; 6) Characterize the sail's electromagnetic interaction with the space environment. This poster presents a top-level assessment of the role of structural <span class="hlt">models</span> in the <span class="hlt">validation</span> process for in-space structural characteristics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5845478','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5845478"><span>An eFTD-VP framework for efficiently generating patient-specific anatomically detailed facial soft tissue <span class="hlt">FE</span> mesh for craniomaxillofacial surgery simulation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Xiaoyan; Kim, Daeseung; Shen, Shunyao; Yuan, Peng; Liu, Siting; Tang, Zhen; Zhang, Guangming; Zhou, Xiaobo; Gateno, Jaime</p> <p>2017-01-01</p> <p>Accurate surgical planning and prediction of craniomaxillofacial surgery outcome requires simulation of soft tissue changes following osteotomy. This can only be achieved by using an anatomically detailed facial soft tissue <span class="hlt">model</span>. The current state-of-the-art of <span class="hlt">model</span> generation is not appropriate to clinical applications due to the time-intensive nature of manual segmentation and volumetric mesh generation. The conventional patient-specific finite element (<span class="hlt">FE</span>) mesh generation methods are to deform a template <span class="hlt">FE</span> mesh to match the shape of a patient based on registration. However, these methods commonly produce element distortion. Additionally, the mesh density for patients depends on that of the template <span class="hlt">model</span>. It could not be adjusted to conduct mesh density sensitivity analysis. In this study, we propose a new framework of patient-specific facial soft tissue <span class="hlt">FE</span> mesh generation. The goal of the developed method is to efficiently generate a high-quality patient-specific hexahedral <span class="hlt">FE</span> mesh with adjustable mesh density while preserving the accuracy in anatomical structure correspondence. Our <span class="hlt">FE</span> mesh is generated by eFace template deformation followed by volumetric parametrization. First, the patient-specific anatomically detailed facial soft tissue <span class="hlt">model</span> (including skin, mucosa, and muscles) is generated by deforming an eFace template <span class="hlt">model</span>. The adaptation of the eFace template <span class="hlt">model</span> is achieved by using a hybrid landmark-based morphing and dense surface fitting approach followed by a thin-plate spline interpolation. Then, high-quality hexahedral mesh is constructed by using volumetric parameterization. The user can control the resolution of hexahedron mesh to best reflect clinicians’ need. Our approach was <span class="hlt">validated</span> using 30 patient <span class="hlt">models</span> and 4 visible human datasets. The generated patient-specific <span class="hlt">FE</span> mesh showed high surface matching accuracy, element quality, and internal structure matching accuracy. They can be directly and effectively used for clinical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29027022','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29027022"><span>An eFTD-VP framework for efficiently generating patient-specific anatomically detailed facial soft tissue <span class="hlt">FE</span> mesh for craniomaxillofacial surgery simulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Xiaoyan; Kim, Daeseung; Shen, Shunyao; Yuan, Peng; Liu, Siting; Tang, Zhen; Zhang, Guangming; Zhou, Xiaobo; Gateno, Jaime; Liebschner, Michael A K; Xia, James J</p> <p>2018-04-01</p> <p>Accurate surgical planning and prediction of craniomaxillofacial surgery outcome requires simulation of soft tissue changes following osteotomy. This can only be achieved by using an anatomically detailed facial soft tissue <span class="hlt">model</span>. The current state-of-the-art of <span class="hlt">model</span> generation is not appropriate to clinical applications due to the time-intensive nature of manual segmentation and volumetric mesh generation. The conventional patient-specific finite element (<span class="hlt">FE</span>) mesh generation methods are to deform a template <span class="hlt">FE</span> mesh to match the shape of a patient based on registration. However, these methods commonly produce element distortion. Additionally, the mesh density for patients depends on that of the template <span class="hlt">model</span>. It could not be adjusted to conduct mesh density sensitivity analysis. In this study, we propose a new framework of patient-specific facial soft tissue <span class="hlt">FE</span> mesh generation. The goal of the developed method is to efficiently generate a high-quality patient-specific hexahedral <span class="hlt">FE</span> mesh with adjustable mesh density while preserving the accuracy in anatomical structure correspondence. Our <span class="hlt">FE</span> mesh is generated by eFace template deformation followed by volumetric parametrization. First, the patient-specific anatomically detailed facial soft tissue <span class="hlt">model</span> (including skin, mucosa, and muscles) is generated by deforming an eFace template <span class="hlt">model</span>. The adaptation of the eFace template <span class="hlt">model</span> is achieved by using a hybrid landmark-based morphing and dense surface fitting approach followed by a thin-plate spline interpolation. Then, high-quality hexahedral mesh is constructed by using volumetric parameterization. The user can control the resolution of hexahedron mesh to best reflect clinicians' need. Our approach was <span class="hlt">validated</span> using 30 patient <span class="hlt">models</span> and 4 visible human datasets. The generated patient-specific <span class="hlt">FE</span> mesh showed high surface matching accuracy, element quality, and internal structure matching accuracy. They can be directly and effectively used for clinical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMMM..454..139O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMMM..454..139O"><span>Weak ferromagnetism along the third-order axis of the <span class="hlt">Fe</span>BO3 crystals caused by <span class="hlt">Fe</span>2+ impurity ions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ovchinnikov, S. G.; Rudenko, V. V.; Vorotynov, A. M.</p> <p>2018-05-01</p> <p>Using the single-ion approximation, the weak ferromagnetic moment σZ(<span class="hlt">Fe</span>2+) along the third-order axis of <span class="hlt">Fe</span>BO3 crystals, which is caused by the contribution of <span class="hlt">Fe</span>2+ ions, has been investigated in the framework of the <span class="hlt">model</span> <span class="hlt">Fe</span>2+ impurity ion -BO3 vacancy. The extreme low-temperature behavior of the total magnetic moment due to the strong dependence of the <span class="hlt">Fe</span>2+ion contribution is predicted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25073464','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25073464"><span><span class="hlt">Modeling</span> and <span class="hlt">validating</span> the cost and clinical pathway of colorectal cancer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Joranger, Paal; Nesbakken, Arild; Hoff, Geir; Sorbye, Halfdan; Oshaug, Arne; Aas, Eline</p> <p>2015-02-01</p> <p>Cancer is a major cause of morbidity and mortality, and colorectal cancer (CRC) is the third most common cancer in the world. The estimated costs of CRC treatment vary considerably, and if CRC costs in a <span class="hlt">model</span> are based on empirically estimated total costs of stage I, II, III, or IV treatments, then they lack some flexibility to capture future changes in CRC treatment. The purpose was 1) to describe how to <span class="hlt">model</span> CRC costs and survival and 2) to <span class="hlt">validate</span> the <span class="hlt">model</span> in a transparent and reproducible way. We applied a semi-Markov <span class="hlt">model</span> with 70 health states and tracked age and time since specific health states (using tunnels and 3-dimensional data matrix). The <span class="hlt">model</span> parameters are based on an observational study at Oslo University Hospital (2049 CRC patients), the National Patient Register, literature, and expert opinion. The target population was patients diagnosed with CRC. The <span class="hlt">model</span> followed the patients diagnosed with CRC from the age of 70 until death or 100 years. The study focused on the perspective of health care payers. The <span class="hlt">model</span> was <span class="hlt">validated</span> for face <span class="hlt">validity</span>, internal and external <span class="hlt">validity</span>, and cross-<span class="hlt">validity</span>. The <span class="hlt">validation</span> showed a satisfactory match with other <span class="hlt">models</span> and empirical estimates for both cost and survival time, without any preceding calibration of the <span class="hlt">model</span>. The <span class="hlt">model</span> can be used to 1) address a range of CRC-related themes (general <span class="hlt">model</span>) like survival and evaluation of the cost of treatment and prevention measures; 2) make predictions from intermediate to final outcomes; 3) estimate changes in resource use and costs due to changing guidelines; and 4) adjust for future changes in treatment and trends over time. The <span class="hlt">model</span> is adaptable to other populations. © The Author(s) 2014.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70189368','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70189368"><span><span class="hlt">Models</span>, <span class="hlt">validation</span>, and applied geochemistry: Issues in science, communication, and philosophy</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nordstrom, D. Kirk</p> <p>2012-01-01</p> <p><span class="hlt">Models</span> have become so fashionable that many scientists and engineers cannot imagine working without them. The predominant use of computer codes to execute <span class="hlt">model</span> calculations has blurred the distinction between code and <span class="hlt">model</span>. The recent controversy regarding <span class="hlt">model</span> <span class="hlt">validation</span> has brought into question what we mean by a ‘model’ and by ‘<span class="hlt">validation</span>.’ It has become apparent that the usual meaning of <span class="hlt">validation</span> may be common in engineering practice and seems useful in legal practice but it is contrary to scientific practice and brings into question our understanding of science and how it can best be applied to such problems as hazardous waste characterization, remediation, and aqueous geochemistry in general. This review summarizes arguments against using the phrase <span class="hlt">model</span> <span class="hlt">validation</span> and examines efforts to <span class="hlt">validate</span> <span class="hlt">models</span> for high-level radioactive waste management and for permitting and monitoring open-pit mines. Part of the controversy comes from a misunderstanding of ‘prediction’ and the need to distinguish logical from temporal prediction. Another problem stems from the difference in the engineering approach contrasted with the scientific approach. The reductionist influence on the way we approach environmental investigations also limits our ability to <span class="hlt">model</span> the interconnected nature of reality. Guidelines are proposed to improve our perceptions and proper utilization of <span class="hlt">models</span>. Use of the word ‘validation’ is strongly discouraged when discussing <span class="hlt">model</span> reliability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1281.1700T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1281.1700T"><span><span class="hlt">Modeling</span> and <span class="hlt">Validation</span> of a Three-Stage Solidification <span class="hlt">Model</span> for Sprays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanner, Franz X.; Feigl, Kathleen; Windhab, Erich J.</p> <p>2010-09-01</p> <p>A three-stage freezing <span class="hlt">model</span> and its <span class="hlt">validation</span> are presented. In the first stage, the cooling of the droplet down to the freezing temperature is described as a convective heat transfer process in turbulent flow. In the second stage, when the droplet has reached the freezing temperature, the solidification process is initiated via nucleation and crystal growth. The latent heat release is related to the amount of heat convected away from the droplet and the rate of solidification is expressed with a freezing progress variable. After completion of the solidification process, in stage three, the cooling of the solidified droplet (particle) is described again by a convective heat transfer process until the particle approaches the temperature of the gaseous environment. The <span class="hlt">model</span> has been <span class="hlt">validated</span> by experimental data of a single cocoa butter droplet suspended in air. The subsequent spray <span class="hlt">validations</span> have been performed with data obtained from a cocoa butter melt in an experimental spray tower using the open-source computational fluid dynamics code KIVA-3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AcGeo..65..931G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AcGeo..65..931G"><span><span class="hlt">Validation</span> of recent geopotential <span class="hlt">models</span> in Tierra Del Fuego</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gomez, Maria Eugenia; Perdomo, Raul; Del Cogliano, Daniel</p> <p>2017-10-01</p> <p>This work presents a <span class="hlt">validation</span> study of global geopotential <span class="hlt">models</span> (GGM) in the region of Fagnano Lake, located in the southern Andes. This is an excellent area for this type of <span class="hlt">validation</span> because it is surrounded by the Andes Mountains, and there is no terrestrial gravity or GNSS/levelling data. However, there are mean lake level (MLL) observations, and its surface is assumed to be almost equipotential. Furthermore, in this article, we propose improved geoid solutions through the Residual Terrain <span class="hlt">Modelling</span> (RTM) approach. Using a global geopotential <span class="hlt">model</span>, the results achieved allow us to conclude that it is possible to use this technique to extend an existing geoid <span class="hlt">model</span> to those regions that lack any information (neither gravimetric nor GNSS/levelling observations). As GGMs have evolved, our results have improved progressively. While the <span class="hlt">validation</span> of EGM2008 with MLL data shows a standard deviation of 35 cm, GOCO05C shows a deviation of 13 cm, similar to the results obtained on land.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1436158-accumulation-fe-oxyhydroxides-peruvian-oxygen-deficient-zone-implies-non-oxygen-dependent-fe-oxidation','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1436158-accumulation-fe-oxyhydroxides-peruvian-oxygen-deficient-zone-implies-non-oxygen-dependent-fe-oxidation"><span>Accumulation of <span class="hlt">Fe</span> oxyhydroxides in the Peruvian oxygen deficient zone implies non-oxygen dependent <span class="hlt">Fe</span> oxidation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Heller, Maija I.; Lam, Phoebe J.; Moffett, James W.; ...</p> <p>2017-05-19</p> <p>Oxygen minimum zones (OMZs) have been proposed to be an important source of dissolved iron (<span class="hlt">Fe</span>) into the interior ocean. However, previous studies in OMZs have shown a sharp decrease in total dissolved <span class="hlt">Fe</span> (d<span class="hlt">Fe</span>) and/or dissolved <span class="hlt">Fe</span>(II) (d<span class="hlt">Fe</span>(II)) concentrations at the shelf-break, despite constant temperature, salinity and continued lack of oxygen across the shelf-break. The loss of both total d<span class="hlt">Fe</span> and d<span class="hlt">Fe</span>(II) suggests a conversion of the d<span class="hlt">Fe</span> to particulate form, but studies that have coupled the reduction-oxidation (redox) speciation of both dissolved and particulate phases have not previously been done. Here in this work, we have measured themore » redox speciation and concentrations of both dissolved and particulate forms of <span class="hlt">Fe</span> in samples collected during the U.S. GEOTRACES Eastern tropical Pacific Zonal Transect (EPZT) cruise in 2013 (GP16). This complete data set allows us to assess possible mechanisms for loss of d<span class="hlt">Fe</span>. We observed an offshore loss of d<span class="hlt">Fe</span>(II) within the oxygen deficient zone (ODZ), where dissolved oxygen is undetectable, accompanied by an increase in total particulate <span class="hlt">Fe</span> (p<span class="hlt">Fe</span>). Total p<span class="hlt">Fe</span> concentrations were highest in the upper ODZ. X-ray absorption spectroscopy revealed that the p<span class="hlt">Fe</span> maximum was primarily in the <span class="hlt">Fe</span>(III) form as <span class="hlt">Fe</span>(III) oxyhydroxides. The remarkable similarity in the distributions of total particulate iron and nitrite suggests a role for nitrite in the oxidation of d<span class="hlt">Fe</span>(II) to p<span class="hlt">Fe</span>(III). Lastly, we present a conceptual <span class="hlt">model</span> for the rapid redox cycling of <span class="hlt">Fe</span> that occurs in ODZs, despite the absence of oxygen.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1436158','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1436158"><span>Accumulation of <span class="hlt">Fe</span> oxyhydroxides in the Peruvian oxygen deficient zone implies non-oxygen dependent <span class="hlt">Fe</span> oxidation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Heller, Maija I.; Lam, Phoebe J.; Moffett, James W.</p> <p></p> <p>Oxygen minimum zones (OMZs) have been proposed to be an important source of dissolved iron (<span class="hlt">Fe</span>) into the interior ocean. However, previous studies in OMZs have shown a sharp decrease in total dissolved <span class="hlt">Fe</span> (d<span class="hlt">Fe</span>) and/or dissolved <span class="hlt">Fe</span>(II) (d<span class="hlt">Fe</span>(II)) concentrations at the shelf-break, despite constant temperature, salinity and continued lack of oxygen across the shelf-break. The loss of both total d<span class="hlt">Fe</span> and d<span class="hlt">Fe</span>(II) suggests a conversion of the d<span class="hlt">Fe</span> to particulate form, but studies that have coupled the reduction-oxidation (redox) speciation of both dissolved and particulate phases have not previously been done. Here in this work, we have measured themore » redox speciation and concentrations of both dissolved and particulate forms of <span class="hlt">Fe</span> in samples collected during the U.S. GEOTRACES Eastern tropical Pacific Zonal Transect (EPZT) cruise in 2013 (GP16). This complete data set allows us to assess possible mechanisms for loss of d<span class="hlt">Fe</span>. We observed an offshore loss of d<span class="hlt">Fe</span>(II) within the oxygen deficient zone (ODZ), where dissolved oxygen is undetectable, accompanied by an increase in total particulate <span class="hlt">Fe</span> (p<span class="hlt">Fe</span>). Total p<span class="hlt">Fe</span> concentrations were highest in the upper ODZ. X-ray absorption spectroscopy revealed that the p<span class="hlt">Fe</span> maximum was primarily in the <span class="hlt">Fe</span>(III) form as <span class="hlt">Fe</span>(III) oxyhydroxides. The remarkable similarity in the distributions of total particulate iron and nitrite suggests a role for nitrite in the oxidation of d<span class="hlt">Fe</span>(II) to p<span class="hlt">Fe</span>(III). Lastly, we present a conceptual <span class="hlt">model</span> for the rapid redox cycling of <span class="hlt">Fe</span> that occurs in ODZs, despite the absence of oxygen.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeCoA.211..174H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeCoA.211..174H"><span>Accumulation of <span class="hlt">Fe</span> oxyhydroxides in the Peruvian oxygen deficient zone implies non-oxygen dependent <span class="hlt">Fe</span> oxidation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heller, Maija I.; Lam, Phoebe J.; Moffett, James W.; Till, Claire P.; Lee, Jong-Mi; Toner, Brandy M.; Marcus, Matthew A.</p> <p>2017-08-01</p> <p>Oxygen minimum zones (OMZs) have been proposed to be an important source of dissolved iron (<span class="hlt">Fe</span>) into the interior ocean. However, previous studies in OMZs have shown a sharp decrease in total dissolved <span class="hlt">Fe</span> (d<span class="hlt">Fe</span>) and/or dissolved <span class="hlt">Fe</span>(II) (d<span class="hlt">Fe</span>(II)) concentrations at the shelf-break, despite constant temperature, salinity and continued lack of oxygen across the shelf-break. The loss of both total d<span class="hlt">Fe</span> and d<span class="hlt">Fe</span>(II) suggests a conversion of the d<span class="hlt">Fe</span> to particulate form, but studies that have coupled the reduction-oxidation (redox) speciation of both dissolved and particulate phases have not previously been done. Here we have measured the redox speciation and concentrations of both dissolved and particulate forms of <span class="hlt">Fe</span> in samples collected during the U.S. GEOTRACES Eastern tropical Pacific Zonal Transect (EPZT) cruise in 2013 (GP16). This complete data set allows us to assess possible mechanisms for loss of d<span class="hlt">Fe</span>. We observed an offshore loss of d<span class="hlt">Fe</span>(II) within the oxygen deficient zone (ODZ), where dissolved oxygen is undetectable, accompanied by an increase in total particulate <span class="hlt">Fe</span> (p<span class="hlt">Fe</span>). Total p<span class="hlt">Fe</span> concentrations were highest in the upper ODZ. X-ray absorption spectroscopy revealed that the p<span class="hlt">Fe</span> maximum was primarily in the <span class="hlt">Fe</span>(III) form as <span class="hlt">Fe</span>(III) oxyhydroxides. The remarkable similarity in the distributions of total particulate iron and nitrite suggests a role for nitrite in the oxidation of d<span class="hlt">Fe</span>(II) to p<span class="hlt">Fe</span>(III). We present a conceptual <span class="hlt">model</span> for the rapid redox cycling of <span class="hlt">Fe</span> that occurs in ODZs, despite the absence of oxygen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26742720','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26742720"><span><span class="hlt">Validation</span> of predicted patellofemoral mechanics in a finite element <span class="hlt">model</span> of the healthy and cruciate-deficient knee.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ali, Azhar A; Shalhoub, Sami S; Cyr, Adam J; Fitzpatrick, Clare K; Maletsky, Lorin P; Rullkoetter, Paul J; Shelburne, Kevin B</p> <p>2016-01-25</p> <p>Healthy patellofemoral (PF) joint mechanics are critical to optimal function of the knee joint. Patellar maltracking may lead to large joint reaction loads and high stresses on the articular cartilage, increasing the risk of cartilage wear and the onset of osteoarthritis. While the mechanical sources of PF joint dysfunction are not well understood, links have been established between PF tracking and abnormal kinematics of the tibiofemoral (TF) joint, specifically following cruciate ligament injury and repair. The objective of this study was to create a <span class="hlt">validated</span> finite element (<span class="hlt">FE</span>) representation of the PF joint in order to predict PF kinematics and quadriceps force across healthy and pathological specimens. Measurements from a series of dynamic in-vitro cadaveric experiments were used to develop finite element <span class="hlt">models</span> of the knee for three specimens. Specimens were loaded under intact, ACL-resected and both ACL and PCL-resected conditions. Finite element <span class="hlt">models</span> of each specimen were constructed and calibrated to the outputs of the intact knee condition, and subsequently used to predict PF kinematics, contact mechanics, quadriceps force, patellar tendon moment arm and patellar tendon angle of the cruciate resected conditions. <span class="hlt">Model</span> results for the intact and cruciate resected trials successfully matched experimental kinematics (avg. RMSE 4.0°, 3.1mm) and peak quadriceps forces (avg. difference 5.6%). Cruciate resections demonstrated either increased patellar tendon loads or increased joint reaction forces. The current study advances the standard for evaluation of PF mechanics through direct <span class="hlt">validation</span> of cruciate-resected conditions including specimen-specific representations of PF anatomy. Copyright © 2015 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25320015','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25320015"><span>Three-dimensional shape optimization of a cemented hip stem and experimental <span class="hlt">validations</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Higa, Masaru; Tanino, Hiromasa; Nishimura, Ikuya; Mitamura, Yoshinori; Matsuno, Takeo; Ito, Hiroshi</p> <p>2015-03-01</p> <p>This study proposes novel optimized stem geometry with low stress values in the cement using a finite element (<span class="hlt">FE</span>) analysis combined with an optimization procedure and experimental measurements of cement stress in vitro. We first optimized an existing stem geometry using a three-dimensional <span class="hlt">FE</span> analysis combined with a shape optimization technique. One of the most important factors in the cemented stem design is to reduce stress in the cement. Hence, in the optimization study, we minimized the largest tensile principal stress in the cement mantle under a physiological loading condition by changing the stem geometry. As the next step, the optimized stem and the existing stem were manufactured to <span class="hlt">validate</span> the usefulness of the numerical <span class="hlt">models</span> and the results of the optimization in vitro. In the experimental study, strain gauges were embedded in the cement mantle to measure the strain in the cement mantle adjacent to the stems. The overall trend of the experimental study was in good agreement with the results of the numerical study, and we were able to reduce the largest stress by more than 50% in both shape optimization and strain gauge measurements. Thus, we could <span class="hlt">validate</span> the usefulness of the numerical <span class="hlt">models</span> and the results of the optimization using the experimental <span class="hlt">models</span>. The optimization employed in this study is a useful approach for developing new stem designs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060031506&hterms=rosenberg&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Drosenberg','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060031506&hterms=rosenberg&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Drosenberg"><span>Cost <span class="hlt">model</span> <span class="hlt">validation</span>: a technical and cultural approach</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hihn, J.; Rosenberg, L.; Roust, K.; Warfield, K.</p> <p>2001-01-01</p> <p>This paper summarizes how JPL's parametric mission cost <span class="hlt">model</span> (PMCM) has been <span class="hlt">validated</span> using both formal statistical methods and a variety of peer and management reviews in order to establish organizational acceptance of the cost <span class="hlt">model</span> estimates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28475651','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28475651"><span>Pharmacokinetic <span class="hlt">modeling</span> of gentamicin in treatment of infective endocarditis: <span class="hlt">Model</span> development and <span class="hlt">validation</span> of existing <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gomes, Anna; van der Wijk, Lars; Proost, Johannes H; Sinha, Bhanu; Touw, Daan J</p> <p>2017-01-01</p> <p>Gentamicin shows large variations in half-life and volume of distribution (Vd) within and between individuals. Thus, monitoring and accurately predicting serum levels are required to optimize effectiveness and minimize toxicity. Currently, two population pharmacokinetic <span class="hlt">models</span> are applied for predicting gentamicin doses in adults. For endocarditis patients the optimal <span class="hlt">model</span> is unknown. We aimed at: 1) creating an optimal <span class="hlt">model</span> for endocarditis patients; and 2) assessing whether the endocarditis and existing <span class="hlt">models</span> can accurately predict serum levels. We performed a retrospective observational two-cohort study: one cohort to parameterize the endocarditis <span class="hlt">model</span> by iterative two-stage Bayesian analysis, and a second cohort to <span class="hlt">validate</span> and compare all three <span class="hlt">models</span>. The Akaike Information Criterion and the weighted sum of squares of the residuals divided by the degrees of freedom were used to select the endocarditis <span class="hlt">model</span>. Median Prediction Error (MDPE) and Median Absolute Prediction Error (MDAPE) were used to test all <span class="hlt">models</span> with the <span class="hlt">validation</span> dataset. We built the endocarditis <span class="hlt">model</span> based on data from the <span class="hlt">modeling</span> cohort (65 patients) with a fixed 0.277 L/h/70kg metabolic clearance, 0.698 (±0.358) renal clearance as fraction of creatinine clearance, and Vd 0.312 (±0.076) L/kg corrected lean body mass. External <span class="hlt">validation</span> with data from 14 <span class="hlt">validation</span> cohort patients showed a similar predictive power of the endocarditis <span class="hlt">model</span> (MDPE -1.77%, MDAPE 4.68%) as compared to the intensive-care (MDPE -1.33%, MDAPE 4.37%) and standard (MDPE -0.90%, MDAPE 4.82%) <span class="hlt">models</span>. All <span class="hlt">models</span> acceptably predicted pharmacokinetic parameters for gentamicin in endocarditis patients. However, these patients appear to have an increased Vd, similar to intensive care patients. Vd mainly determines the height of peak serum levels, which in turn correlate with bactericidal activity. In order to maintain simplicity, we advise to use the existing intensive-care <span class="hlt">model</span> in clinical practice to avoid</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5419648','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5419648"><span>Pharmacokinetic <span class="hlt">modeling</span> of gentamicin in treatment of infective endocarditis: <span class="hlt">Model</span> development and <span class="hlt">validation</span> of existing <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>van der Wijk, Lars; Proost, Johannes H.; Sinha, Bhanu; Touw, Daan J.</p> <p>2017-01-01</p> <p>Gentamicin shows large variations in half-life and volume of distribution (Vd) within and between individuals. Thus, monitoring and accurately predicting serum levels are required to optimize effectiveness and minimize toxicity. Currently, two population pharmacokinetic <span class="hlt">models</span> are applied for predicting gentamicin doses in adults. For endocarditis patients the optimal <span class="hlt">model</span> is unknown. We aimed at: 1) creating an optimal <span class="hlt">model</span> for endocarditis patients; and 2) assessing whether the endocarditis and existing <span class="hlt">models</span> can accurately predict serum levels. We performed a retrospective observational two-cohort study: one cohort to parameterize the endocarditis <span class="hlt">model</span> by iterative two-stage Bayesian analysis, and a second cohort to <span class="hlt">validate</span> and compare all three <span class="hlt">models</span>. The Akaike Information Criterion and the weighted sum of squares of the residuals divided by the degrees of freedom were used to select the endocarditis <span class="hlt">model</span>. Median Prediction Error (MDPE) and Median Absolute Prediction Error (MDAPE) were used to test all <span class="hlt">models</span> with the <span class="hlt">validation</span> dataset. We built the endocarditis <span class="hlt">model</span> based on data from the <span class="hlt">modeling</span> cohort (65 patients) with a fixed 0.277 L/h/70kg metabolic clearance, 0.698 (±0.358) renal clearance as fraction of creatinine clearance, and Vd 0.312 (±0.076) L/kg corrected lean body mass. External <span class="hlt">validation</span> with data from 14 <span class="hlt">validation</span> cohort patients showed a similar predictive power of the endocarditis <span class="hlt">model</span> (MDPE -1.77%, MDAPE 4.68%) as compared to the intensive-care (MDPE -1.33%, MDAPE 4.37%) and standard (MDPE -0.90%, MDAPE 4.82%) <span class="hlt">models</span>. All <span class="hlt">models</span> acceptably predicted pharmacokinetic parameters for gentamicin in endocarditis patients. However, these patients appear to have an increased Vd, similar to intensive care patients. Vd mainly determines the height of peak serum levels, which in turn correlate with bactericidal activity. In order to maintain simplicity, we advise to use the existing intensive-care <span class="hlt">model</span> in clinical practice to avoid</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1237412','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1237412"><span>A defect density-based constitutive crystal plasticity framework for <span class="hlt">modeling</span> the plastic deformation of <span class="hlt">Fe</span>-Cr-Al cladding alloys subsequent to irradiation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Patra, Anirban; Wen, Wei; Martinez Saez, Enrique</p> <p>2016-02-05</p> <p>It is essential to understand the deformation behavior of these <span class="hlt">Fe</span>-Cr-Al alloys, in order to be able to develop <span class="hlt">models</span> for predicting their mechanical response under varied loading conditions. Interaction of dislocations with the radiation-induced defects governs the crystallographic deformation mechanisms. A crystal plasticity framework is employed to <span class="hlt">model</span> these mechanisms in <span class="hlt">Fe</span>-Cr-Al alloys. This work builds on a previously developed defect density-based crystal plasticity <span class="hlt">model</span> for bcc metals and alloys, with necessary modifications made to account for the defect substructure observed in <span class="hlt">Fe</span>-Cr-Al alloys. The <span class="hlt">model</span> is implemented in a Visco-Plastic Self Consistent (VPSC) framework, to predict the mechanicalmore » behavior under quasi-static loading.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22364718-empirical-determination-einstein-coefficient-ratios-bright-fe-ii-lines','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22364718-empirical-determination-einstein-coefficient-ratios-bright-fe-ii-lines"><span>EMPIRICAL DETERMINATION OF EINSTEIN A-COEFFICIENT RATIOS OF BRIGHT [<span class="hlt">Fe</span> II] LINES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Giannini, T.; Antoniucci, S.; Nisini, B.</p> <p></p> <p>The Einstein spontaneous rates (A-coefficients) of <span class="hlt">Fe</span>{sup +} lines have been computed by several authors with results that differ from each other by up to 40%. Consequently, <span class="hlt">models</span> for line emissivities suffer from uncertainties that in turn affect the determination of the physical conditions at the base of line excitation. We provide an empirical determination of the A-coefficient ratios of bright [<span class="hlt">Fe</span> II] lines that would represent both a <span class="hlt">valid</span> benchmark for theoretical computations and a reference for the physical interpretation of the observed lines. With the ESO-Very Large Telescope X-shooter instrument between 3000 Å and 24700 Å, we obtainedmore » a spectrum of the bright Herbig-Haro object HH 1. We detect around 100 [<span class="hlt">Fe</span> II] lines, some of which with a signal-to-noise ratios ≥100. Among these latter lines, we selected those emitted by the same level, whose dereddened intensity ratios are direct functions of the Einstein A-coefficient ratios. From the same X-shooter spectrum, we got an accurate estimate of the extinction toward HH 1 through intensity ratios of atomic species, H I recombination lines and H{sub 2} ro-vibrational transitions. We provide seven reliable A-coefficient ratios between bright [<span class="hlt">Fe</span> II] lines, which are compared with the literature determinations. In particular, the A-coefficient ratios involving the brightest near-infrared lines (λ12570/λ16440 and λ13209/λ16440) are in better agreement with the predictions by the Quinet et al. relativistic Hartree-Fock <span class="hlt">model</span>. However, none of the theoretical <span class="hlt">models</span> predict A-coefficient ratios in agreement with all of our determinations. We also show that literature data of near-infrared intensity ratios better agree with our determinations than with theoretical expectations.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..478V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..478V"><span>Predicting the ungauged basin: <span class="hlt">model</span> <span class="hlt">validation</span> and realism assessment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Emmerik, Tim; Mulder, Gert; Eilander, Dirk; Piet, Marijn; Savenije, Hubert</p> <p>2016-04-01</p> <p>The hydrological decade on Predictions in Ungauged Basins (PUB) [1] led to many new insights in <span class="hlt">model</span> development, calibration strategies, data acquisition and uncertainty analysis. Due to a limited amount of published studies on genuinely ungauged basins, <span class="hlt">model</span> <span class="hlt">validation</span> and realism assessment of <span class="hlt">model</span> outcome has not been discussed to a great extent. With this study [2] we aim to contribute to the discussion on how one can determine the value and <span class="hlt">validity</span> of a hydrological <span class="hlt">model</span> developed for an ungauged basin. As in many cases no local, or even regional, data are available, alternative methods should be applied. Using a PUB case study in a genuinely ungauged basin in southern Cambodia, we give several examples of how one can use different types of soft data to improve <span class="hlt">model</span> design, calibrate and <span class="hlt">validate</span> the <span class="hlt">model</span>, and assess the realism of the <span class="hlt">model</span> output. A rainfall-runoff <span class="hlt">model</span> was coupled to an irrigation reservoir, allowing the use of additional and unconventional data. The <span class="hlt">model</span> was mainly forced with remote sensing data, and local knowledge was used to constrain the parameters. <span class="hlt">Model</span> realism assessment was done using data from surveys. This resulted in a successful reconstruction of the reservoir dynamics, and revealed the different hydrological characteristics of the two topographical classes. We do not present a generic approach that can be transferred to other ungauged catchments, but we aim to show how clever <span class="hlt">model</span> design and alternative data acquisition can result in a valuable hydrological <span class="hlt">model</span> for ungauged catchments. [1] Sivapalan, M., Takeuchi, K., Franks, S., Gupta, V., Karambiri, H., Lakshmi, V., et al. (2003). IAHS decade on predictions in ungauged basins (PUB), 2003-2012: shaping an exciting future for the hydrological sciences. Hydrol. Sci. J. 48, 857-880. doi: 10.1623/hysj.48.6.857.51421 [2] van Emmerik, T., Mulder, G., Eilander, D., Piet, M. and Savenije, H. (2015). Predicting the ungauged basin: <span class="hlt">model</span> <span class="hlt">validation</span> and realism assessment</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28043174','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28043174"><span><span class="hlt">Validation</span> and calibration of structural <span class="hlt">models</span> that combine information from multiple sources.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dahabreh, Issa J; Wong, John B; Trikalinos, Thomas A</p> <p>2017-02-01</p> <p>Mathematical <span class="hlt">models</span> that attempt to capture structural relationships between their components and combine information from multiple sources are increasingly used in medicine. Areas covered: We provide an overview of methods for <span class="hlt">model</span> <span class="hlt">validation</span> and calibration and survey studies comparing alternative approaches. Expert commentary: <span class="hlt">Model</span> <span class="hlt">validation</span> entails a confrontation of <span class="hlt">models</span> with data, background knowledge, and other <span class="hlt">models</span>, and can inform judgments about <span class="hlt">model</span> credibility. Calibration involves selecting parameter values to improve the agreement of <span class="hlt">model</span> outputs with data. When the goal of <span class="hlt">modeling</span> is quantitative inference on the effects of interventions or forecasting, calibration can be viewed as estimation. This view clarifies issues related to parameter identifiability and facilitates formal <span class="hlt">model</span> <span class="hlt">validation</span> and the examination of consistency among different sources of information. In contrast, when the goal of <span class="hlt">modeling</span> is the generation of qualitative insights about the <span class="hlt">modeled</span> phenomenon, calibration is a rather informal process for selecting inputs that result in <span class="hlt">model</span> behavior that roughly reproduces select aspects of the <span class="hlt">modeled</span> phenomenon and cannot be equated to an estimation procedure. Current empirical research on <span class="hlt">validation</span> and calibration methods consists primarily of methodological appraisals or case-studies of alternative techniques and cannot address the numerous complex and multifaceted methodological decisions that <span class="hlt">modelers</span> must make. Further research is needed on different approaches for developing and <span class="hlt">validating</span> complex <span class="hlt">models</span> that combine evidence from multiple sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27078566','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27078566"><span>The locations of recent supernovae near the Sun from <span class="hlt">modelling</span> (60)<span class="hlt">Fe</span> transport.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Breitschwerdt, D; Feige, J; Schulreich, M M; de Avillez, M A; Dettbarn, C; Fuchs, B</p> <p>2016-04-07</p> <p>The signature of (60)<span class="hlt">Fe</span> in deep-sea crusts indicates that one or more supernovae exploded in the solar neighbourhood about 2.2 million years ago. Recent isotopic analysis is consistent with a core-collapse or electron-capture supernova that occurred 60 to 130 parsecs from the Sun. Moreover, peculiarities in the cosmic ray spectrum point to a nearby supernova about two million years ago. The Local Bubble of hot, diffuse plasma, in which the Solar System is embedded, originated from 14 to 20 supernovae within a moving group, whose surviving members are now in the Scorpius-Centaurus stellar association. Here we report calculations of the most probable trajectories and masses of the supernova progenitors, and hence their explosion times and sites. The (60)<span class="hlt">Fe</span> signal arises from two supernovae at distances between 90 and 100 parsecs. The closest occurred 2.3 million years ago at present-day galactic coordinates l = 327°, b = 11°, and the second-closest exploded about 1.5 million years ago at l = 343°, b = 25°, with masses of 9.2 and 8.8 times the solar mass, respectively. The remaining supernovae, which formed the Local Bubble, contribute to a smaller extent because they happened at larger distances and longer ago ((60)<span class="hlt">Fe</span> has a half-life of 2.6 million years). There are uncertainties relating to the nucleosynthesis yields and the loss of (60)<span class="hlt">Fe</span> during transport, but they do not influence the relative distribution of (60)<span class="hlt">Fe</span> in the crust layers, and therefore our <span class="hlt">model</span> reproduces the measured relative abundances very well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3933172','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3933172"><span>A multiscale MD–<span class="hlt">FE</span> <span class="hlt">model</span> of diffusion in composite media with internal surface interaction based on numerical homogenization procedure</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kojic, M.; Milosevic, M.; Kojic, N.; Kim, K.; Ferrari, M.; Ziemys, A.</p> <p>2014-01-01</p> <p>Mass transport by diffusion within composite materials may depend not only on internal microstructural geometry, but also on the chemical interactions between the transported substance and the material of the microstructure. Retrospectively, there is a gap in methods and theory to connect material microstructure properties with macroscale continuum diffusion characteristics. Here we present a new hierarchical multiscale <span class="hlt">model</span> for diffusion within composite materials that couples material microstructural geometry and interactions between diffusing particles and the material matrix. This <span class="hlt">model</span>, which bridges molecular dynamics (MD) and the finite element (<span class="hlt">FE</span>) method, is employed to construct a continuum diffusion <span class="hlt">model</span> based on a novel numerical homogenization procedure. The procedure is general and robust for evaluating constitutive material parameters of the continuum <span class="hlt">model</span>. These parameters include the traditional bulk diffusion coefficients and, additionally, the distances from the solid surface accounting for surface interaction effects. We implemented our <span class="hlt">models</span> to glucose diffusion through the following two geometrical/material configurations: tightly packed silica nanospheres, and a complex fibrous structure surrounding nanospheres. Then, rhodamine 6G diffusion analysis through an aga-rose gel network was performed, followed by a <span class="hlt">model</span> <span class="hlt">validation</span> using our experimental results. The microstructural <span class="hlt">model</span>, numerical homogenization and continuum <span class="hlt">model</span> offer a new platform for <span class="hlt">modeling</span> and predicting mass diffusion through complex biological environment and within composite materials that are used in a wide range of applications, like drug delivery and nanoporous catalysts. PMID:24578582</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14555358','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14555358"><span><span class="hlt">Validation</span> analysis of probabilistic <span class="hlt">models</span> of dietary exposure to food additives.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gilsenan, M B; Thompson, R L; Lambe, J; Gibney, M J</p> <p>2003-10-01</p> <p>The <span class="hlt">validity</span> of a range of simple conceptual <span class="hlt">models</span> designed specifically for the estimation of food additive intakes using probabilistic analysis was assessed. <span class="hlt">Modelled</span> intake estimates that fell below traditional conservative point estimates of intake and above 'true' additive intakes (calculated from a reference database at brand level) were considered to be in a <span class="hlt">valid</span> region. <span class="hlt">Models</span> were developed for 10 food additives by combining food intake data, the probability of an additive being present in a food group and additive concentration data. Food intake and additive concentration data were entered as raw data or as a lognormal distribution, and the probability of an additive being present was entered based on the per cent brands or the per cent eating occasions within a food group that contained an additive. Since the three <span class="hlt">model</span> components assumed two possible modes of input, the <span class="hlt">validity</span> of eight (2(3)) <span class="hlt">model</span> combinations was assessed. All <span class="hlt">model</span> inputs were derived from the reference database. An iterative approach was employed in which the <span class="hlt">validity</span> of individual <span class="hlt">model</span> components was assessed first, followed by <span class="hlt">validation</span> of full conceptual <span class="hlt">models</span>. While the distribution of intake estimates from <span class="hlt">models</span> fell below conservative intakes, which assume that the additive is present at maximum permitted levels (MPLs) in all foods in which it is permitted, intake estimates were not consistently above 'true' intakes. These analyses indicate the need for more complex <span class="hlt">models</span> for the estimation of food additive intakes using probabilistic analysis. Such <span class="hlt">models</span> should incorporate information on market share and/or brand loyalty.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28877309','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28877309"><span>A Finite Element <span class="hlt">Model</span> of a Midsize Male for Simulating Pedestrian Accidents.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Untaroiu, Costin D; Pak, Wansoo; Meng, Yunzhu; Schap, Jeremy; Koya, Bharath; Gayzik, Scott</p> <p>2018-01-01</p> <p>Pedestrians represent one of the most vulnerable road users and comprise nearly 22% the road crash-related fatalities in the world. Therefore, protection of pedestrians in car-to-pedestrian collisions (CPC) has recently generated increased attention with regulations involving three subsystem tests. The development of a finite element (<span class="hlt">FE</span>) pedestrian <span class="hlt">model</span> could provide a complementary component that characterizes the whole-body response of vehicle-pedestrian interactions and assesses the pedestrian injuries. The main goal of this study was to develop and to <span class="hlt">validate</span> a simplified full body <span class="hlt">FE</span> <span class="hlt">model</span> corresponding to a 50th male pedestrian in standing posture (M50-PS). The <span class="hlt">FE</span> <span class="hlt">model</span> mesh and defined material properties are based on a 50th percentile male occupant <span class="hlt">model</span>. The lower limb-pelvis and lumbar spine regions of the human <span class="hlt">model</span> were <span class="hlt">validated</span> against the postmortem human surrogate (PMHS) test data recorded in four-point lateral knee bending tests, pelvic\\abdomen\\shoulder\\thoracic impact tests, and lumbar spine bending tests. Then, a pedestrian-to-vehicle impact simulation was performed using the whole pedestrian <span class="hlt">model</span>, and the results were compared to corresponding PMHS tests. Overall, the simulation results showed that lower leg response is mostly within the boundaries of PMHS corridors. In addition, the <span class="hlt">model</span> shows the capability to predict the most common lower extremity injuries observed in pedestrian accidents. Generally, the <span class="hlt">validated</span> pedestrian <span class="hlt">model</span> may be used by safety researchers in the design of front ends of new vehicles in order to increase pedestrian protection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5774711','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5774711"><span>Empirical <span class="hlt">validation</span> of an agent-based <span class="hlt">model</span> of wood markets in Switzerland</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hilty, Lorenz M.; Lemm, Renato; Thees, Oliver</p> <p>2018-01-01</p> <p>We present an agent-based <span class="hlt">model</span> of wood markets and show our efforts to <span class="hlt">validate</span> this <span class="hlt">model</span> using empirical data from different sources, including interviews, workshops, experiments, and official statistics. Own surveys closed gaps where data was not available. Our approach to <span class="hlt">model</span> <span class="hlt">validation</span> used a variety of techniques, including the replication of historical production amounts, prices, and survey results, as well as a historical case study of a large sawmill entering the market and becoming insolvent only a few years later. <span class="hlt">Validating</span> the <span class="hlt">model</span> using this case provided additional insights, showing how the <span class="hlt">model</span> can be used to simulate scenarios of resource availability and resource allocation. We conclude that the outcome of the rigorous <span class="hlt">validation</span> qualifies the <span class="hlt">model</span> to simulate scenarios concerning resource availability and allocation in our study region. PMID:29351300</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22412861-study-perpendicular-anisotropy-l1-sub-fept-pseudo-spin-valves-using-micromagnetic-trilayer-model','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22412861-study-perpendicular-anisotropy-l1-sub-fept-pseudo-spin-valves-using-micromagnetic-trilayer-model"><span>Study of perpendicular anisotropy L1{sub 0}-<span class="hlt">Fe</span>Pt pseudo spin valves using a micromagnetic trilayer <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ho, Pin, E-mail: hopin@mit.edu; Data Storage Institute, Agency of Science, Technology and Research - A*STAR, 117608 Singapore; Evans, Richard F. L.</p> <p>2015-06-07</p> <p>A trilayer micromagnetic <span class="hlt">model</span> based on the Landau-Lifshitz-Bloch equation of motion is utilized to study the properties of L1{sub 0}-<span class="hlt">Fe</span>Pt/TiN/L1{sub 0}-<span class="hlt">Fe</span>Pt pseudo spin valves (PSVs) in direct comparison with experiment. Theoretical studies give an insight on the crystallographic texture, magnetic properties, reversal behavior, interlayer coupling effects, and magneto-transport properties of the PSVs, in particular, with varying thickness of the top L1{sub 0}-<span class="hlt">Fe</span>Pt and TiN spacer. We show that morphological changes in the <span class="hlt">Fe</span>Pt layers, induced by varying the <span class="hlt">Fe</span>Pt layer thickness, lead to different hysteresis behaviors of the samples, caused by changes in the interlayer and intralayer exchange couplings. Suchmore » effects are important for the optimization of the PSVs due to the relationship between the magnetic properties, domain structures, and the magnetoresistance of the device.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4186979','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4186979"><span>CheS-Mapper 2.0 for visual <span class="hlt">validation</span> of (Q)SAR <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>Background Sound statistical <span class="hlt">validation</span> is important to evaluate and compare the overall performance of (Q)SAR <span class="hlt">models</span>. However, classical <span class="hlt">validation</span> does not support the user in better understanding the properties of the <span class="hlt">model</span> or the underlying data. Even though, a number of visualization tools for analyzing (Q)SAR information in small molecule datasets exist, integrated visualization methods that allow the investigation of <span class="hlt">model</span> <span class="hlt">validation</span> results are still lacking. Results We propose visual <span class="hlt">validation</span>, as an approach for the graphical inspection of (Q)SAR <span class="hlt">model</span> <span class="hlt">validation</span> results. The approach applies the 3D viewer CheS-Mapper, an open-source application for the exploration of small molecules in virtual 3D space. The present work describes the new functionalities in CheS-Mapper 2.0, that facilitate the analysis of (Q)SAR information and allows the visual <span class="hlt">validation</span> of (Q)SAR <span class="hlt">models</span>. The tool enables the comparison of <span class="hlt">model</span> predictions to the actual activity in feature space. The approach is generic: It is <span class="hlt">model</span>-independent and can handle physico-chemical and structural input features as well as quantitative and qualitative endpoints. Conclusions Visual <span class="hlt">validation</span> with CheS-Mapper enables analyzing (Q)SAR information in the data and indicates how this information is employed by the (Q)SAR <span class="hlt">model</span>. It reveals, if the endpoint is <span class="hlt">modeled</span> too specific or too generic and highlights common properties of misclassified compounds. Moreover, the researcher can use CheS-Mapper to inspect how the (Q)SAR <span class="hlt">model</span> predicts activity cliffs. The CheS-Mapper software is freely available at http://ches-mapper.org. Graphical abstract Comparing actual and predicted activity values with CheS-Mapper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1339249','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1339249"><span>Development of a Rhodobacter capsulatus self-reporting <span class="hlt">model</span> system for optimizing light-dependent, [<span class="hlt">FeFe</span>]-hydrogenase-driven H 2 production</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wecker, Matt S. A.; Beaton, Stephen E.; Chado, Robert A.</p> <p></p> <p>The photosynthetic bacterium Rhodobacter capsulatus normally photoproduces H 2 as a by-product of its nitrogenase-catalyzed nitrogen-fixing activity. Such H 2 production, however, is expensive from a metabolic perspective, requiring nearly four times as many photons as the equivalent algal hydrogenase-based system. Here we report the insertion of a Clostridium acetobutylicum [<span class="hlt">FeFe</span>]-hydrogenase and its three attendant hydrogenase assembly proteins into an R. capsulatus strain lacking its native uptake hydrogenase. Further, this strain is modified to fluoresce upon sensing H 2. The resulting strain photoproduces H 2 and self-reports its own H 2 production through fluorescence. Furthermore, this <span class="hlt">model</span> system represents amore » unique method of developing hydrogenase-based H 2 production in R. capsulatus, may serve as a powerful system for in vivo directed evolution of hydrogenases and hydrogenase-associated genes, and provides a means of screening for increased metabolic production of H 2.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1339249-development-rhodobacter-capsulatus-self-reporting-model-system-optimizing-light-dependent-fefe-hydrogenase-driven-h2-production','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1339249-development-rhodobacter-capsulatus-self-reporting-model-system-optimizing-light-dependent-fefe-hydrogenase-driven-h2-production"><span>Development of a Rhodobacter capsulatus self-reporting <span class="hlt">model</span> system for optimizing light-dependent, [<span class="hlt">FeFe</span>]-hydrogenase-driven H 2 production</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Wecker, Matt S. A.; Beaton, Stephen E.; Chado, Robert A.; ...</p> <p>2016-08-17</p> <p>The photosynthetic bacterium Rhodobacter capsulatus normally photoproduces H 2 as a by-product of its nitrogenase-catalyzed nitrogen-fixing activity. Such H 2 production, however, is expensive from a metabolic perspective, requiring nearly four times as many photons as the equivalent algal hydrogenase-based system. Here we report the insertion of a Clostridium acetobutylicum [<span class="hlt">FeFe</span>]-hydrogenase and its three attendant hydrogenase assembly proteins into an R. capsulatus strain lacking its native uptake hydrogenase. Further, this strain is modified to fluoresce upon sensing H 2. The resulting strain photoproduces H 2 and self-reports its own H 2 production through fluorescence. Furthermore, this <span class="hlt">model</span> system represents amore » unique method of developing hydrogenase-based H 2 production in R. capsulatus, may serve as a powerful system for in vivo directed evolution of hydrogenases and hydrogenase-associated genes, and provides a means of screening for increased metabolic production of H 2.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100025022','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100025022"><span>Description of a Website Resource for Turbulence <span class="hlt">Modeling</span> Verification and <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rumsey, Christopher L.; Smith, Brian R.; Huang, George P.</p> <p>2010-01-01</p> <p>The activities of the Turbulence <span class="hlt">Model</span> Benchmarking Working Group - which is a subcommittee of the American Institute of Aeronautics and Astronautics (AIAA) Fluid Dynamics Technical Committee - are described. The group s main purpose is to establish a web-based repository for Reynolds-averaged Navier-Stokes turbulence <span class="hlt">model</span> documentation, including verification and <span class="hlt">validation</span> cases. This turbulence <span class="hlt">modeling</span> resource has been established based on feedback from a survey on what is needed to achieve consistency and repeatability in turbulence <span class="hlt">model</span> implementation and usage, and to document and disseminate information on new turbulence <span class="hlt">models</span> or improvements to existing <span class="hlt">models</span>. The various components of the website are described in detail: description of turbulence <span class="hlt">models</span>, turbulence <span class="hlt">model</span> readiness rating system, verification cases, <span class="hlt">validation</span> cases, <span class="hlt">validation</span> databases, and turbulence manufactured solutions. An outline of future plans of the working group is also provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4303487','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4303487"><span><span class="hlt">Modeling</span> and <span class="hlt">Validation</span> of Microwave Ablations with Internal Vaporization</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chiang, Jason; Birla, Sohan; Bedoya, Mariajose; Jones, David; Subbiah, Jeyam; Brace, Christopher L.</p> <p>2014-01-01</p> <p>Numerical simulation is increasingly being utilized for computer-aided design of treatment devices, analysis of ablation growth, and clinical treatment planning. Simulation <span class="hlt">models</span> to date have incorporated electromagnetic wave propagation and heat conduction, but not other relevant physics such as water vaporization and mass transfer. Such physical changes are particularly noteworthy during the intense heat generation associated with microwave heating. In this work, a numerical <span class="hlt">model</span> was created that integrates microwave heating with water vapor generation and transport by using porous media assumptions in the tissue domain. The heating physics of the water vapor <span class="hlt">model</span> was <span class="hlt">validated</span> through temperature measurements taken at locations 5, 10 and 20 mm away from the heating zone of the microwave antenna in homogenized ex vivo bovine liver setup. Cross-sectional area of water vapor transport was <span class="hlt">validated</span> through intra-procedural computed tomography (CT) during microwave ablations in homogenized ex vivo bovine liver. Iso-density contours from CT images were compared to vapor concentration contours from the numerical <span class="hlt">model</span> at intermittent time points using the Jaccard Index. In general, there was an improving correlation in ablation size dimensions as the ablation procedure proceeded, with a Jaccard Index of 0.27, 0.49, 0.61, 0.67 and 0.69 at 1, 2, 3, 4, and 5 minutes. This study demonstrates the feasibility and <span class="hlt">validity</span> of incorporating water vapor concentration into thermal ablation simulations and <span class="hlt">validating</span> such <span class="hlt">models</span> experimentally. PMID:25330481</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110013451','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110013451"><span>Highlights of Transient Plume Impingement <span class="hlt">Model</span> <span class="hlt">Validation</span> and Applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Woronowicz, Michael</p> <p>2011-01-01</p> <p>This paper describes highlights of an ongoing <span class="hlt">validation</span> effort conducted to assess the viability of applying a set of analytic point source transient free molecule equations to <span class="hlt">model</span> behavior ranging from molecular effusion to rocket plumes. The <span class="hlt">validation</span> effort includes encouraging comparisons to both steady and transient studies involving experimental data and direct simulation Monte Carlo results. Finally, this <span class="hlt">model</span> is applied to describe features of two exotic transient scenarios involving NASA Goddard Space Flight Center satellite programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70018272','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70018272"><span>Alternative solution <span class="hlt">model</span> for the ternary carbonate system CaCO3 - MgCO3 - <span class="hlt">Fe</span>CO3 - II. Calibration of a combined ordering <span class="hlt">model</span> and mixing <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McSwiggen, P.L.</p> <p>1993-01-01</p> <p>Earlier attempts at solution <span class="hlt">models</span> for the ternary carbonate system have been unable to adequately accommodate the cation ordering which occurs in some of the carbonate phases. The carbonate solution <span class="hlt">model</span> of this study combines a Margules type of interaction <span class="hlt">model</span> with a Bragg-Williams type of ordering <span class="hlt">model</span>. The ordering <span class="hlt">model</span> determines the equilibrium state of order for a crystal, from which the cation distribution within the lattice can be obtained. The interaction <span class="hlt">model</span> addresses the effect that mixing different cation species within a given cation layer has on the total free energy of the system. An ordering <span class="hlt">model</span> was derived, based on the Bragg-Williams approach; it is applicable to ternary systems involving three cations substituting on two sites, and contains three ordering energy parameters (WCaMg, WCa<span class="hlt">Fe</span>, and WCaMg<span class="hlt">Fe</span>). The solution <span class="hlt">model</span> of this study involves six Margules-type interaction parameters (W12, W21, W13, W31, W23, and W32). Values for the two sets of energy parameters were calculated from experimental data and from compositional relationships in natural assemblages. ?? 1993 Springer-Verlag.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21043864-oxidation-deprotonation-synthetic-fe-sup-ii-fe-sup-iii-oxy-hydroxycarbonate-green-rust-ray-photoelectron-study','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21043864-oxidation-deprotonation-synthetic-fe-sup-ii-fe-sup-iii-oxy-hydroxycarbonate-green-rust-ray-photoelectron-study"><span>Oxidation and deprotonation of synthetic <span class="hlt">Fe</span>{sup II}-<span class="hlt">Fe</span>{sup III} (oxy)hydroxycarbonate Green Rust: An X-ray photoelectron study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Mullet, M.; Guillemin, Y.; Ruby, C.</p> <p></p> <p>X-ray photoelectron spectroscopy (XPS) was used to investigate chemical bonding and distribution of iron and oxygen species at the surface of Green Rusts (GRs). GRs with variable composition, i.e. <span class="hlt">Fe</span>{sup II}{sub 6(1-x)}<span class="hlt">Fe</span>{sup III}{sub 6x}O{sub 12}H{sub 2(7-3x)} CO{sub 3}.3H{sub 2}O where the <span class="hlt">Fe</span>{sup III} molar fraction of the positively charged hydroxide sheets, x=[<span class="hlt">Fe(III)]/[Fe</span>(total)] belongs to [1/3, 1], were synthesised under an inert atmosphere. The broadened <span class="hlt">Fe</span>(2p{sub 3/2}) spectra were fitted using Gupta and Sen multiplets peaks and additional satellite and surface features. The [<span class="hlt">Fe(III)]/[Fe</span>(total)] surface atomic ratios closely agree with the x ratios expected from the bulk composition, which gives amore » high degree of confidence on the <span class="hlt">validity</span> of the proposed fitting procedure. The valence band spectra are also reported and show dependencies on iron speciation. The O(1s) spectra revealed the presence of O{sup 2-}, OH{sup -} species and adsorbed water. The hydroxyl component decreases with increasing x values, i.e. with the amount of ferric iron, while the oxide component increases. This study provides direct spectroscopic evidence of the deprotonation of hydroxyl groups that occurs simultaneously with the oxidation of ferrous iron within the GR structure. - Graphical abstract: X-ray photoelectron spectroscopy (XPS) is used to investigate chemical bonding and distribution of iron and oxygen species at the surface of Green Rust (GR) compounds. First spectroscopic evidence of the deprotonation of hydroxyls groups occurring simultaneously to the oxidation of <span class="hlt">Fe</span>(II) into <span class="hlt">Fe</span>(III) species is provided.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24737833','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24737833"><span>PACIC Instrument: disentangling dimensions using published <span class="hlt">validation</span> <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Iglesias, K; Burnand, B; Peytremann-Bridevaux, I</p> <p>2014-06-01</p> <p>To better understand the structure of the Patient Assessment of Chronic Illness Care (PACIC) instrument. More specifically to test all published <span class="hlt">validation</span> <span class="hlt">models</span>, using one single data set and appropriate statistical tools. <span class="hlt">Validation</span> study using data from cross-sectional survey. A population-based sample of non-institutionalized adults with diabetes residing in Switzerland (canton of Vaud). French version of the 20-items PACIC instrument (5-point response scale). We conducted <span class="hlt">validation</span> analyses using confirmatory factor analysis (CFA). The original five-dimension <span class="hlt">model</span> and other published <span class="hlt">models</span> were tested with three types of CFA: based on (i) a Pearson estimator of variance-covariance matrix, (ii) a polychoric correlation matrix and (iii) a likelihood estimation with a multinomial distribution for the manifest variables. All <span class="hlt">models</span> were assessed using loadings and goodness-of-fit measures. The analytical sample included 406 patients. Mean age was 64.4 years and 59% were men. Median of item responses varied between 1 and 4 (range 1-5), and range of missing values was between 5.7 and 12.3%. Strong floor and ceiling effects were present. Even though loadings of the tested <span class="hlt">models</span> were relatively high, the only <span class="hlt">model</span> showing acceptable fit was the 11-item single-dimension <span class="hlt">model</span>. PACIC was associated with the expected variables of the field. Our results showed that the <span class="hlt">model</span> considering 11 items in a single dimension exhibited the best fit for our data. A single score, in complement to the consideration of single-item results, might be used instead of the five dimensions usually described. © The Author 2014. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1597476','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1597476"><span>Sealed reticulocyte ghosts. An experimental <span class="hlt">model</span> for the study of <span class="hlt">Fe</span>2+ transport.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Núñez, M T; Escobar, A; Ahumada, A; Gonzalez-Sepulveda, M</p> <p>1992-06-05</p> <p>Sealed right-side-out reticulocyte ghosts transported and accumulated iron offered as 59<span class="hlt">Fe</span>(2+)-ascorbate (Km = 1.1 microM). The uptake of iron by ghosts presented the characteristics of a transporter-mediated process: it responded to osmotic challenge, the rate of transport increased when iron was present in the opposing side, and the transport rate showed the temperature dependence typical of membrane-mediated processes. The transport of iron was dependent on an associated influx of Cl- in order to keep electroneutrality. Other transition metals, such as Cu2+, Zn2+, and Co2+, inhibited the transport of <span class="hlt">Fe</span>2+. The overall characteristics of the system make reticulocyte sealed ghosts a very useful <span class="hlt">model</span> in determining the basic mechanisms of membrane iron transport.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23708470','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23708470"><span>Cross-<span class="hlt">validation</span> of an employee safety climate <span class="hlt">model</span> in Malaysia.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bahari, Siti Fatimah; Clarke, Sharon</p> <p>2013-06-01</p> <p>Whilst substantial research has investigated the nature of safety climate, and its importance as a leading indicator of organisational safety, much of this research has been conducted with Western industrial samples. The current study focuses on the cross-<span class="hlt">validation</span> of a safety climate <span class="hlt">model</span> in the non-Western industrial context of Malaysian manufacturing. The first-order factorial <span class="hlt">validity</span> of Cheyne et al.'s (1998) [Cheyne, A., Cox, S., Oliver, A., Tomas, J.M., 1998. <span class="hlt">Modelling</span> safety climate in the prediction of levels of safety activity. Work and Stress, 12(3), 255-271] <span class="hlt">model</span> was tested, using confirmatory factor analysis, in a Malaysian sample. Results showed that the <span class="hlt">model</span> fit indices were below accepted levels, indicating that the original Cheyne et al. (1998) safety climate <span class="hlt">model</span> was not supported. An alternative three-factor <span class="hlt">model</span> was developed using exploratory factor analysis. Although these findings are not consistent with previously reported cross-<span class="hlt">validation</span> studies, we argue that previous studies have focused on <span class="hlt">validation</span> across Western samples, and that the current study demonstrates the need to take account of cultural factors in the development of safety climate <span class="hlt">models</span> intended for use in non-Western contexts. The results have important implications for the transferability of existing safety climate <span class="hlt">models</span> across cultures (for example, in global organisations) and highlight the need for future research to examine cross-cultural issues in relation to safety climate. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1440310-co-bridged-cluster-intermediates-catalytic-mechanism-fefe-hydrogenase-cai','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1440310-co-bridged-cluster-intermediates-catalytic-mechanism-fefe-hydrogenase-cai"><span>CO-Bridged H-Cluster Intermediates in the Catalytic Mechanism of [<span class="hlt">FeFe</span>]-Hydrogenase CaI</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Ratzloff, Michael W.; Artz, Jacob H.; Mulder, David W.; ...</p> <p>2018-05-23</p> <p>The [<span class="hlt">FeFe</span>]-hydrogenases ([<span class="hlt">FeFe</span>] H 2ases) catalyze reversible H 2 activation at the H-cluster, which is composed of a [4<span class="hlt">Fe</span>-4S] H subsite linked by a cysteine thiolate to a bridged, organometallic [2<span class="hlt">Fe</span>-2S] ([2<span class="hlt">Fe</span>] H) subsite. Profoundly different geometric <span class="hlt">models</span> of the H-cluster redox states that orchestrate the electron/proton transfer steps of H 2 bond activation have been proposed. We have examined this question in the [<span class="hlt">FeFe</span>] H 2ase I from Clostridium acetobutylicum (CaI) by Fourier-transform infrared (FTIR) spectroscopy with temperature annealing and H/D isotope exchange to identify the relevant redox states and define catalytic transitions. One-electron reduction of H ox ledmore » to formation of H redH + ([4<span class="hlt">Fe</span>-4S] H 2+-<span class="hlt">Fe</span> I-<span class="hlt">Fe</span> I) and H red' ([4<span class="hlt">Fe</span>-4S] H 1+-<span class="hlt">Fe</span> II-<span class="hlt">Fe</span> I), with both states characterized by low frequency μ-CO IR modes consistent with a fully bridged [2<span class="hlt">Fe</span>] H. Similar μ-CO IR modes were also identified for H redH + of the [<span class="hlt">FeFe</span>] H 2ase from Chlamydomonas reinhardtii (CrHydA1). The CaI proton-transfer variant C298S showed enrichment of an H/D isotope-sensitive μ-CO mode, a component of the hydride bound H-cluster IR signal, H hyd. Equilibrating CaI with increasing amounts of NaDT, and probed at cryogenic temperatures, showed H redH + was converted to H hyd. Over an increasing temperature range from 10 to 260 K catalytic turnover led to loss of Hhyd and appearance of H ox, consistent with enzymatic turnover and H 2 formation. The results show for CaI that the μ-CO of [2<span class="hlt">Fe</span>] H remains bridging for all of the 'H red' states and that H redH + is on pathway to H hyd and H 2 evolution in the catalytic mechanism. Here, this provides a blueprint for designing small molecule catalytic analogs« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1440310-co-bridged-cluster-intermediates-catalytic-mechanism-fefe-hydrogenase-cai','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1440310-co-bridged-cluster-intermediates-catalytic-mechanism-fefe-hydrogenase-cai"><span>CO-Bridged H-Cluster Intermediates in the Catalytic Mechanism of [<span class="hlt">FeFe</span>]-Hydrogenase CaI</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ratzloff, Michael W.; Artz, Jacob H.; Mulder, David W.</p> <p></p> <p>The [<span class="hlt">FeFe</span>]-hydrogenases ([<span class="hlt">FeFe</span>] H 2ases) catalyze reversible H 2 activation at the H-cluster, which is composed of a [4<span class="hlt">Fe</span>-4S] H subsite linked by a cysteine thiolate to a bridged, organometallic [2<span class="hlt">Fe</span>-2S] ([2<span class="hlt">Fe</span>] H) subsite. Profoundly different geometric <span class="hlt">models</span> of the H-cluster redox states that orchestrate the electron/proton transfer steps of H 2 bond activation have been proposed. We have examined this question in the [<span class="hlt">FeFe</span>] H 2ase I from Clostridium acetobutylicum (CaI) by Fourier-transform infrared (FTIR) spectroscopy with temperature annealing and H/D isotope exchange to identify the relevant redox states and define catalytic transitions. One-electron reduction of H ox ledmore » to formation of H redH + ([4<span class="hlt">Fe</span>-4S] H 2+-<span class="hlt">Fe</span> I-<span class="hlt">Fe</span> I) and H red' ([4<span class="hlt">Fe</span>-4S] H 1+-<span class="hlt">Fe</span> II-<span class="hlt">Fe</span> I), with both states characterized by low frequency μ-CO IR modes consistent with a fully bridged [2<span class="hlt">Fe</span>] H. Similar μ-CO IR modes were also identified for H redH + of the [<span class="hlt">FeFe</span>] H 2ase from Chlamydomonas reinhardtii (CrHydA1). The CaI proton-transfer variant C298S showed enrichment of an H/D isotope-sensitive μ-CO mode, a component of the hydride bound H-cluster IR signal, H hyd. Equilibrating CaI with increasing amounts of NaDT, and probed at cryogenic temperatures, showed H redH + was converted to H hyd. Over an increasing temperature range from 10 to 260 K catalytic turnover led to loss of Hhyd and appearance of H ox, consistent with enzymatic turnover and H 2 formation. The results show for CaI that the μ-CO of [2<span class="hlt">Fe</span>] H remains bridging for all of the 'H red' states and that H redH + is on pathway to H hyd and H 2 evolution in the catalytic mechanism. Here, this provides a blueprint for designing small molecule catalytic analogs« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29792026','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29792026"><span>CO-Bridged H-Cluster Intermediates in the Catalytic Mechanism of [<span class="hlt">FeFe</span>]-Hydrogenase CaI.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ratzloff, Michael W; Artz, Jacob H; Mulder, David W; Collins, Reuben T; Furtak, Thomas E; King, Paul W</p> <p>2018-06-20</p> <p>The [<span class="hlt">FeFe</span>]-hydrogenases ([<span class="hlt">FeFe</span>] H 2 ases) catalyze reversible H 2 activation at the H-cluster, which is composed of a [4<span class="hlt">Fe</span>-4S] H subsite linked by a cysteine thiolate to a bridged, organometallic [2<span class="hlt">Fe</span>-2S] ([2<span class="hlt">Fe</span>] H ) subsite. Profoundly different geometric <span class="hlt">models</span> of the H-cluster redox states that orchestrate the electron/proton transfer steps of H 2 bond activation have been proposed. We have examined this question in the [<span class="hlt">FeFe</span>] H 2 ase I from Clostridium acetobutylicum (CaI) by Fourier-transform infrared (FTIR) spectroscopy with temperature annealing and H/D isotope exchange to identify the relevant redox states and define catalytic transitions. One-electron reduction of H ox led to formation of H red H + ([4<span class="hlt">Fe</span>-4S] H 2+ -<span class="hlt">Fe</span> I -<span class="hlt">Fe</span> I ) and H red ' ([4<span class="hlt">Fe</span>-4S] H 1+ -<span class="hlt">Fe</span> II -<span class="hlt">Fe</span> I ), with both states characterized by low frequency μ-CO IR modes consistent with a fully bridged [2<span class="hlt">Fe</span>] H . Similar μ-CO IR modes were also identified for H red H + of the [<span class="hlt">FeFe</span>] H 2 ase from Chlamydomonas reinhardtii (CrHydA1). The CaI proton-transfer variant C298S showed enrichment of an H/D isotope-sensitive μ-CO mode, a component of the hydride bound H-cluster IR signal, H hyd . Equilibrating CaI with increasing amounts of NaDT, and probed at cryogenic temperatures, showed H red H + was converted to H hyd . Over an increasing temperature range from 10 to 260 K catalytic turnover led to loss of H hyd and appearance of H ox , consistent with enzymatic turnover and H 2 formation. The results show for CaI that the μ-CO of [2<span class="hlt">Fe</span>] H remains bridging for all of the "H red " states and that H red H + is on pathway to H hyd and H 2 evolution in the catalytic mechanism. These results provide a blueprint for designing small molecule catalytic analogs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MS%26E..322b2061G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MS%26E..322b2061G"><span>Study on <span class="hlt">validation</span> method for femur finite element <span class="hlt">model</span> under multiple loading conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guan, Fengjiao; Zhang, Guanjun; Liu, Jie; Wang, Shujing; Luo, Xu</p> <p>2018-03-01</p> <p>Acquisition of accurate and reliable constitutive parameters related to bio-tissue materials was beneficial to improve biological fidelity of a Finite Element (<span class="hlt">FE</span>) <span class="hlt">model</span> and predict impact damages more effectively. In this paper, a femur <span class="hlt">FE</span> <span class="hlt">model</span> was established under multiple loading conditions with diverse impact positions. Then, based on sequential response surface method and genetic algorithms, the material parameters identification was transformed to a multi-response optimization problem. Finally, the simulation results successfully coincided with force-displacement curves obtained by numerous experiments. Thus, computational accuracy and efficiency of the entire inverse calculation process were enhanced. This method was able to effectively reduce the computation time in the inverse process of material parameters. Meanwhile, the material parameters obtained by the proposed method achieved higher accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21561647','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21561647"><span>Fracture simulation of restored teeth using a continuum damage mechanics failure <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Haiyan; Li, Jianying; Zou, Zhenmin; Fok, Alex Siu-Lun</p> <p>2011-07-01</p> <p>The aim of this paper is to <span class="hlt">validate</span> the use of a finite-element (<span class="hlt">FE</span>) based continuum damage mechanics (CDM) failure <span class="hlt">model</span> to simulate the debonding and fracture of restored teeth. Fracture testing of plastic <span class="hlt">model</span> teeth, with or without a standard Class-II MOD (mesial-occusal-distal) restoration, was carried out to investigate their fracture behavior. In parallel, 2D <span class="hlt">FE</span> <span class="hlt">models</span> of the teeth are constructed and analyzed using the commercial <span class="hlt">FE</span> software ABAQUS. A CDM failure <span class="hlt">model</span>, implemented into ABAQUS via the user element subroutine (UEL), is used to simulate the debonding and/or final fracture of the <span class="hlt">model</span> teeth under a compressive load. The material parameters needed for the CDM <span class="hlt">model</span> to simulate fracture are obtained through separate mechanical tests. The predicted results are then compared with the experimental data of the fracture tests to <span class="hlt">validate</span> the failure <span class="hlt">model</span>. The failure processes of the intact and restored <span class="hlt">model</span> teeth are successfully reproduced by the simulation. However, the fracture parameters obtained from testing small specimens need to be adjusted to account for the size effect. The results indicate that the CDM <span class="hlt">model</span> is a viable <span class="hlt">model</span> for the prediction of debonding and fracture in dental restorations. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16..412J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16..412J"><span>Using airborne laser scanning profiles to <span class="hlt">validate</span> marine geoid <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Julge, Kalev; Gruno, Anti; Ellmann, Artu; Liibusk, Aive; Oja, Tõnis</p> <p>2014-05-01</p> <p>Airborne laser scanning (ALS) is a remote sensing method which utilizes LiDAR (Light Detection And Ranging) technology. The datasets collected are important sources for large range of scientific and engineering applications. Mostly the ALS is used to measure terrain surfaces for compilation of Digital Elevation <span class="hlt">Models</span> but it can also be used in other applications. This contribution focuses on usage of ALS system for measuring sea surface heights and <span class="hlt">validating</span> gravimetric geoid <span class="hlt">models</span> over marine areas. This is based on the ALS ability to register echoes of LiDAR pulse from the water surface. A case study was carried out to analyse the possibilities for <span class="hlt">validating</span> marine geoid <span class="hlt">models</span> by using ALS profiles. A test area at the southern shores of the Gulf of Finland was selected for regional geoid <span class="hlt">validation</span>. ALS measurements were carried out by the Estonian Land Board in spring 2013 at different altitudes and using different scan rates. The one wavelength Leica ALS50-II laser scanner on board of a small aircraft was used to determine the sea level (with respect to the GRS80 reference ellipsoid), which follows roughly the equipotential surface of the Earth's gravity field. For the <span class="hlt">validation</span> a high-resolution (1'x2') regional gravimetric GRAV-GEOID2011 <span class="hlt">model</span> was used. This geoid <span class="hlt">model</span> covers the entire area of Estonia and surrounding waters of the Baltic Sea. The fit between the geoid <span class="hlt">model</span> and GNSS/levelling data within the Estonian dry land revealed RMS of residuals ±1… ±2 cm. Note that such fitting <span class="hlt">validation</span> cannot proceed over marine areas. Therefore, an ALS observation-based methodology was developed to evaluate the GRAV-GEOID2011 quality over marine areas. The accuracy of acquired ALS dataset were analyzed, also an optimal width of nadir-corridor containing good quality ALS data was determined. Impact of ALS scan angle range and flight altitude to obtainable vertical accuracy were investigated as well. The quality of point cloud is analysed by cross</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Nanos...720117D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Nanos...720117D"><span>Nanocrystalline <span class="hlt">Fe-Fe</span>2O3 particle-deposited N-doped graphene as an activity-modulated Pt-free electrocatalyst for oxygen reduction reaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dhavale, Vishal M.; Singh, Santosh K.; Nadeema, Ayasha; Gaikwad, Sachin S.; Kurungot, Sreekumar</p> <p>2015-11-01</p> <p>The size-controlled growth of nanocrystalline <span class="hlt">Fe-Fe</span>2O3 particles (2-3 nm) and their concomitant dispersion on N-doped graphene (<span class="hlt">Fe-Fe</span>2O3/NGr) could be attained when the mutually assisted redox reaction between NGr and <span class="hlt">Fe</span>3+ ions could be controlled within the aqueous droplets of a water-in-oil emulsion. The synergistic interaction existing between <span class="hlt">Fe-Fe</span>2O3 and NGr helped the system to narrow down the overpotential for the oxygen reduction reaction (ORR) by bringing a significant positive shift to the reduction onset potential, which is just 15 mV higher than its Pt-counterpart. In addition, the half-wave potential (E1/2) of <span class="hlt">Fe-Fe</span>2O3/NGr is found to be improved by a considerable amount of 135 mV in comparison to the system formed by dispersing <span class="hlt">Fe-Fe</span>2O3 nanoparticles on reduced graphene oxide (<span class="hlt">Fe-Fe</span>2O3/RGO), which indicates the presence of a higher number of active sites in <span class="hlt">Fe-Fe</span>2O3/NGr. Despite this, the ORR kinetics of <span class="hlt">Fe-Fe</span>2O3/NGr are found to be shifted significantly to the preferred 4-electron-transfer pathway compared to NGr and <span class="hlt">Fe-Fe</span>2O3/RGO. Consequently, the H2O2% was found to be reduced by 78.3% for <span class="hlt">Fe-Fe</span>2O3/NGr (13.0%) in comparison to <span class="hlt">Fe-Fe</span>2O3/RGO (51.2%) and NGr (41.0%) at -0.30 V (vs. Hg/HgO). This difference in the yield of H2O2 formed between the systems along with the improvements observed in terms of the oxygen reduction onset and E1/2 in the case of <span class="hlt">Fe-Fe</span>2O3/NGr reveals the activity modulation achieved for the latter is due to the coexistence of factors such as the presence of the mixed valancies of iron nanoparticles, small size and homogeneous distribution of <span class="hlt">Fe-Fe</span>2O3 nanoparticles and the electronic modifications induced by the doped nitrogen in NGr. A controlled interplay of these factors looks like worked favorably in the case of <span class="hlt">Fe-Fe</span>2O3/NGr. As a realistic system level <span class="hlt">validation</span>, <span class="hlt">Fe-Fe</span>2O3/NGr was employed as the cathode electrode of a single cell in a solid alkaline electrolyte membrane fuel cell (AEMFC). The system could display an open</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22584088-heat-capacity-magnetic-properties-fluoride-csfe-sup-fe-sup-sub-defect-pyrochlore-structure','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22584088-heat-capacity-magnetic-properties-fluoride-csfe-sup-fe-sup-sub-defect-pyrochlore-structure"><span>Heat capacity and magnetic properties of fluoride Cs<span class="hlt">Fe</span>{sup 2+}<span class="hlt">Fe</span>{sup 3+}F{sub 6} with defect pyrochlore structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gorev, M.V., E-mail: gorev@iph.krasn.ru; Institute of Engineering Physics and Radio Electronics, Siberian State University, 660074 Krasnoyarsk; Flerov, I.N.</p> <p>2016-05-15</p> <p>Heat capacity, Mössbauer and Raman spectra as well as magnetic properties of fluoride Cs<span class="hlt">Fe</span>{sub 2}F{sub 6} with defect pyrochlore structure were studied. In addition to recently found above room temperature three successive structural transformations Pnma-Imma-I4{sub 1}amd-Fd-3m, phase transition of antiferromagnetic nature with the 13.7 K Neel temperature and a broad heat capacity anomaly with a maximum at about 30 K were observed. The room temperature symmetry Pnma is unchanged at least down to 7 K. Simple <span class="hlt">model</span> of indirect bond used to estimate the exchange interactions and to propose a magnetic structure <span class="hlt">model</span>. - Graphical abstract: The ordered arrangement ofmore » <span class="hlt">Fe</span>{sup 2+} and <span class="hlt">Fe</span>{sup 3+} ions in high-spin states as well as antiferromagnetic phase transition followed by significant magnetic frustrations were found in pyrocholore-related Cs<span class="hlt">Fe</span>{sup 2+}<span class="hlt">Fe</span>{sup 3+}F{sub 6}. A magnetic structure was proposed using a simple <span class="hlt">model</span> of indirect bonds. - Highlights: • The Pnma structure in pyrocholore Cs<span class="hlt">Fe</span>{sub 2}F{sub 6} is stable down to helium temperature. • Mössbauer spectra confirmed the ordering of <span class="hlt">Fe</span>{sup 2+} and <span class="hlt">Fe</span>{sup 3+} ions. • Antiferromagnetic transformation and significant magnetic frustrations are found. • Experimental magnetic entropy agrees with entropy for <span class="hlt">Fe</span> ions in high-spin state. • Superexchange interactions were calculated and a magnetic structure was proposed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140010184','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010184"><span>Predicting Pilot Error in Nextgen: Pilot Performance <span class="hlt">Modeling</span> and <span class="hlt">Validation</span> Efforts</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wickens, Christopher; Sebok, Angelia; Gore, Brian; Hooey, Becky</p> <p>2012-01-01</p> <p>We review 25 articles presenting 5 general classes of computational <span class="hlt">models</span> to predict pilot error. This more targeted review is placed within the context of the broader review of computational <span class="hlt">models</span> of pilot cognition and performance, including such aspects as <span class="hlt">models</span> of situation awareness or pilot-automation interaction. Particular emphasis is placed on the degree of <span class="hlt">validation</span> of such <span class="hlt">models</span> against empirical pilot data, and the relevance of the <span class="hlt">modeling</span> and <span class="hlt">validation</span> efforts to Next Gen technology and procedures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3245580','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3245580"><span>Is the Acute NMDA Receptor Hypofunction a <span class="hlt">Valid</span> <span class="hlt">Model</span> of Schizophrenia?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Adell, Albert; Jiménez-Sánchez, Laura; López-Gil, Xavier; Romón, Tamara</p> <p>2012-01-01</p> <p>Several genetic, neurodevelopmental, and pharmacological animal <span class="hlt">models</span> of schizophrenia have been established. This short review examines the <span class="hlt">validity</span> of one of the most used pharmacological <span class="hlt">model</span> of the illness, ie, the acute administration of N-methyl-D-aspartate (NMDA) receptor antagonists in rodents. In some cases, data on chronic or prenatal NMDA receptor antagonist exposure have been introduced for comparison. The face <span class="hlt">validity</span> of acute NMDA receptor blockade is granted inasmuch as hyperlocomotion and stereotypies induced by phencyclidine, ketamine, and MK-801 are regarded as a surrogate for the positive symptoms of schizophrenia. In addition, the loss of parvalbumin-containing cells (which is one of the most compelling finding in postmortem schizophrenia brain) following NMDA receptor blockade adds construct <span class="hlt">validity</span> to this <span class="hlt">model</span>. However, the lack of changes in glutamic acid decarboxylase (GAD67) is at variance with human studies. It is possible that changes in GAD67 are more reflective of the neurodevelopmental condition of schizophrenia. Finally, the <span class="hlt">model</span> also has predictive <span class="hlt">validity</span>, in that its behavioral and transmitter activation in rodents are responsive to antipsychotic treatment. Overall, although not devoid of drawbacks, the acute administration of NMDA receptor antagonists can be considered as a good <span class="hlt">model</span> of schizophrenia bearing a satisfactory degree of <span class="hlt">validity</span>. PMID:21965469</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JPhD...43o5301P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JPhD...43o5301P"><span>The effect of <span class="hlt">Fe</span>F2 on the magneto-optic response in <span class="hlt">Fe</span>F2/<span class="hlt">Fe/Fe</span>F2 sandwiches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pištora, J.; Lesňák, M.; Lišková, E.; Višňovský, Š.; Harward, I.; Maslankiewicz, P.; Balin, K.; Celinski, Z.; Mistrík, J.; Yamaguchi, T.; Lopusnik, R.; Vlček, J.</p> <p>2010-04-01</p> <p>The room temperature optical constants n and k of MBE grown <span class="hlt">Fe</span>F2 films are reported. Because of poor chemical stability, <span class="hlt">Fe</span>F2 had to be coated with a protective Au layer. Reflection spectral ellipsometry in the photon energy range between 1.3 and 5.2 eV was performed on structures with a typical profile Au(0.5 nm)/<span class="hlt">Fe</span>F2(120 nm)/Au(30 nm)/Ag(20 nm)/<span class="hlt">Fe</span>(0.6 nm) grown on GaAs(0 0 1) substrate. The spectra of n and k in <span class="hlt">Fe</span>F2 were subsequently employed in the design of <span class="hlt">Fe</span>F2/<span class="hlt">Fe/Fe</span>F2 sandwiches considered as magneto-optic (MO) sensors for weak microwave currents. Their MO response was evaluated using reflection MO (Kerr) spectroscopy at polar magnetization. The present results may be of interest in MO studies of magnetic nanostructures with <span class="hlt">Fe/Fe</span>F2/<span class="hlt">Fe</span>, including MO magnetometry and MO magnetic domain imaging.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMMM..419..517G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMMM..419..517G"><span>Coercivity scaling in antidot lattices in <span class="hlt">Fe</span>, Ni, and Ni<span class="hlt">Fe</span> thin films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gräfe, Joachim; Schütz, Gisela; Goering, Eberhard J.</p> <p>2016-12-01</p> <p>Antidot lattices can be used to artificially engineer magnetic properties in thin films, however, a conclusive <span class="hlt">model</span> that describes the coercivity enhancement in this class of magnetic nano-structures has so far not been found. We prepared <span class="hlt">Fe</span>, Ni, and Ni<span class="hlt">Fe</span> thin films and patterned each with 21 square antidot lattices with different geometric parameters and measured their hysteretic behavior. On the basis of this extensive dataset we are able to provide a <span class="hlt">model</span> that can describe both the coercivity scaling over a wide range of geometric lattice parameters and the influence of different materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25179855','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25179855"><span>A new framework to enhance the interpretation of external <span class="hlt">validation</span> studies of clinical prediction <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Debray, Thomas P A; Vergouwe, Yvonne; Koffijberg, Hendrik; Nieboer, Daan; Steyerberg, Ewout W; Moons, Karel G M</p> <p>2015-03-01</p> <p>It is widely acknowledged that the performance of diagnostic and prognostic prediction <span class="hlt">models</span> should be assessed in external <span class="hlt">validation</span> studies with independent data from "different but related" samples as compared with that of the development sample. We developed a framework of methodological steps and statistical methods for analyzing and enhancing the interpretation of results from external <span class="hlt">validation</span> studies of prediction <span class="hlt">models</span>. We propose to quantify the degree of relatedness between development and <span class="hlt">validation</span> samples on a scale ranging from reproducibility to transportability by evaluating their corresponding case-mix differences. We subsequently assess the <span class="hlt">models</span>' performance in the <span class="hlt">validation</span> sample and interpret the performance in view of the case-mix differences. Finally, we may adjust the <span class="hlt">model</span> to the <span class="hlt">validation</span> setting. We illustrate this three-step framework with a prediction <span class="hlt">model</span> for diagnosing deep venous thrombosis using three <span class="hlt">validation</span> samples with varying case mix. While one external <span class="hlt">validation</span> sample merely assessed the <span class="hlt">model</span>'s reproducibility, two other samples rather assessed <span class="hlt">model</span> transportability. The performance in all <span class="hlt">validation</span> samples was adequate, and the <span class="hlt">model</span> did not require extensive updating to correct for miscalibration or poor fit to the <span class="hlt">validation</span> settings. The proposed framework enhances the interpretation of findings at external <span class="hlt">validation</span> of prediction <span class="hlt">models</span>. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28882201','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28882201"><span>B. subtilis as a <span class="hlt">Model</span> for Studying the Assembly of <span class="hlt">Fe</span>-S Clusters in Gram-Positive Bacteria.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dos Santos, Patricia C</p> <p>2017-01-01</p> <p>Complexes of iron and sulfur (<span class="hlt">Fe</span>-S clusters) are widely distributed in nature and participate in essential biochemical reactions. The biological formation of <span class="hlt">Fe</span>-S clusters involves dedicated pathways responsible for the mobilization of sulfur, the assembly of <span class="hlt">Fe</span>-S clusters, and the transfer of these clusters to target proteins. Genomic analysis of Bacillus subtilis and other Gram-positive bacteria indicated the presence of only one <span class="hlt">Fe</span>-S cluster biosynthesis pathway, which is distinct in number of components and organization from previously studied systems. B. subtilis has been used as a <span class="hlt">model</span> system for the characterization of cysteine desulfurases responsible for sulfur mobilization reactions in the biogenesis of <span class="hlt">Fe</span>-S clusters and other sulfur-containing cofactors. Cysteine desulfurases catalyze the cleavage of the C-S bond from the amino acid cysteine and subsequent transfer of sulfur to acceptor molecules. These reactions can be monitored by the rate of alanine formation, the first product in the reaction, and sulfide formation, a byproduct of reactions performed under reducing conditions. The assembly of <span class="hlt">Fe</span>-S clusters on protein scaffolds and the transfer of these clusters to target acceptors are determined through a combination of spectroscopic methods probing the rate of cluster assembly and transfer. This chapter provides a description of reactions promoting the assembly of <span class="hlt">Fe</span>-S clusters in bacteria as well as methods used to study functions of each biosynthetic component and identify mechanistic differences employed by these enzymes across different pathways. © 2017 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28574450','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28574450"><span>Stable ABTS Immobilized in the MIL-100(<span class="hlt">Fe</span>) Metal-Organic Framework as an Efficient Mediator for Laccase-Catalyzed Decolorization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Youxun; Geng, Yuanyuan; Yan, Mingyang; Huang, Juan</p> <p>2017-06-02</p> <p>The successful encapsulation of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), a well-known laccase mediator, within a mesoporous metal-organic framework sample (i.e., MIL-100(<span class="hlt">Fe</span>)) was achieved using a one-pot hydrothermal synthetic method. The as-prepared ABTS@MIL-100(<span class="hlt">Fe</span>) was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, nitrogen sorption, and cyclic voltammetry (CV). Our ABTS@MIL-100(<span class="hlt">Fe</span>)-based electrode exhibited an excellent electrochemical response, indicating that MIL-100(<span class="hlt">Fe</span>) provides an appropriate microenvironment for the immobilization and electroactivity of ABTS molecules. ABTS@MIL-100(<span class="hlt">Fe</span>) was then evaluated as an immobilized laccase mediator for dye removal using indigo carmine (IC) as a <span class="hlt">model</span> dye. Through the application of laccase in combination with a free (ABTS) or immobilized (ABTS@MIL-100(<span class="hlt">Fe</span>)) mediator, decolorization yields of 95% and 94%, respectively, were obtained for IC after 50 min. In addition, following seven reuse cycles of ABTS@MIL-100(<span class="hlt">Fe</span>) for dye treatment, a decolorization yield of 74% was obtained. Dye decolorization occurred through the breakdown of the chromophoric group by the Laccase/ABTS@MIL-100(<span class="hlt">Fe</span>) system, and a catalytic mechanism was proposed. We therefore expect that the stability, reusability, and <span class="hlt">validity</span> of ABTS@MIL-100(<span class="hlt">Fe</span>) as a laccase mediator potentially render it a promising tool for dye removal, in addition to reducing the high running costs and potential toxicity associated with synthetic mediators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22070329','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22070329"><span>MRI-based <span class="hlt">modeling</span> for radiocarpal joint mechanics: <span class="hlt">validation</span> criteria and results for four specimen-specific <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fischer, Kenneth J; Johnson, Joshua E; Waller, Alexander J; McIff, Terence E; Toby, E Bruce; Bilgen, Mehmet</p> <p>2011-10-01</p> <p>The objective of this study was to <span class="hlt">validate</span> the MRI-based joint contact <span class="hlt">modeling</span> methodology in the radiocarpal joints by comparison of <span class="hlt">model</span> results with invasive specimen-specific radiocarpal contact measurements from four cadaver experiments. We used a single <span class="hlt">validation</span> criterion for multiple outcome measures to characterize the utility and overall <span class="hlt">validity</span> of the <span class="hlt">modeling</span> approach. For each experiment, a Pressurex film and a Tekscan sensor were sequentially placed into the radiocarpal joints during simulated grasp. Computer <span class="hlt">models</span> were constructed based on MRI visualization of the cadaver specimens without load. Images were also acquired during the loaded configuration used with the direct experimental measurements. Geometric surface <span class="hlt">models</span> of the radius, scaphoid and lunate (including cartilage) were constructed from the images acquired without the load. The carpal bone motions from the unloaded state to the loaded state were determined using a series of 3D image registrations. Cartilage thickness was assumed uniform at 1.0 mm with an effective compressive modulus of 4 MPa. <span class="hlt">Validation</span> was based on experimental versus <span class="hlt">model</span> contact area, contact force, average contact pressure and peak contact pressure for the radioscaphoid and radiolunate articulations. Contact area was also measured directly from images acquired under load and compared to the experimental and <span class="hlt">model</span> data. Qualitatively, there was good correspondence between the MRI-based <span class="hlt">model</span> data and experimental data, with consistent relative size, shape and location of radioscaphoid and radiolunate contact regions. Quantitative data from the <span class="hlt">model</span> generally compared well with the experimental data for all specimens. Contact area from the MRI-based <span class="hlt">model</span> was very similar to the contact area measured directly from the images. For all outcome measures except average and peak pressures, at least two specimen <span class="hlt">models</span> met the <span class="hlt">validation</span> criteria with respect to experimental measurements for both articulations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/983694','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/983694"><span>Some guidance on preparing <span class="hlt">validation</span> plans for the DART Full System <span class="hlt">Models</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gray, Genetha Anne; Hough, Patricia Diane; Hills, Richard Guy</p> <p>2009-03-01</p> <p>Planning is an important part of computational <span class="hlt">model</span> verification and <span class="hlt">validation</span> (V&V) and the requisite planning document is vital for effectively executing the plan. The document provides a means of communicating intent to the typically large group of people, from program management to analysts to test engineers, who must work together to complete the <span class="hlt">validation</span> activities. This report provides guidelines for writing a <span class="hlt">validation</span> plan. It describes the components of such a plan and includes important references and resources. While the initial target audience is the DART Full System <span class="hlt">Model</span> teams in the nuclear weapons program, the guidelines are generallymore » applicable to other <span class="hlt">modeling</span> efforts. Our goal in writing this document is to provide a framework for consistency in <span class="hlt">validation</span> plans across weapon systems, different types of <span class="hlt">models</span>, and different scenarios. Specific details contained in any given <span class="hlt">validation</span> plan will vary according to application requirements and available resources.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Principles+AND+Instrumental+AND+Analysis&pg=3&id=EJ801298','ERIC'); return false;" href="https://eric.ed.gov/?q=Principles+AND+Instrumental+AND+Analysis&pg=3&id=EJ801298"><span><span class="hlt">Validation</span> of an Evaluation <span class="hlt">Model</span> for Learning Management Systems</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kim, S. W.; Lee, M. G.</p> <p>2008-01-01</p> <p>This study aims to <span class="hlt">validate</span> a <span class="hlt">model</span> for evaluating learning management systems (LMS) used in e-learning fields. A survey of 163 e-learning experts, regarding 81 <span class="hlt">validation</span> items developed through literature review, was used to ascertain the importance of the criteria. A concise list of explanatory constructs, including two principle factors, was…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23471871','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23471871"><span>Energies and spin states of <span class="hlt">Fe</span>S(0/-), <span class="hlt">Fe</span>S2(0/-), <span class="hlt">Fe</span>2S2(0/-), <span class="hlt">Fe</span>3S4(0/-), and <span class="hlt">Fe</span>4S4(0/-) clusters.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Yan-Ni; Wang, Shengguang; Wang, Tao; Gao, Rui; Geng, Chun-Yu; Li, Yong-Wang; Wang, Jianguo; Jiao, Haijun</p> <p>2013-04-15</p> <p>The structures and energies of the electronic ground states of the <span class="hlt">Fe</span>S(0/-), <span class="hlt">Fe</span>S2(0/-), <span class="hlt">Fe</span>2S2(0/-), <span class="hlt">Fe</span>3S4(0/-), and <span class="hlt">Fe</span>4S4(0/-) neutral and anionic clusters have been computed systematically with nine computational methods in combination with seven basis sets. The computed adiabatic electronic affinities (AEA) have been compared with available experimental data. Most reasonable agreements between theory and experiment have been found for both hybrid B3LYP and B3PW91 functionals in conjugation with 6-311+G* and QZVP basis sets. Detailed comparisons between the available experimental and computed AEA data at the B3LYP/6-311+G* level identified the electronic ground state of (5)Δ for <span class="hlt">Fe</span>S, (4)Δ for <span class="hlt">Fe</span>S(-), (5)B2 for <span class="hlt">Fe</span>S2, (6)A1 for <span class="hlt">Fe</span>S2(-), (1)A1 for <span class="hlt">Fe</span>2S2, (8)A' for <span class="hlt">Fe</span>2S2(-), (5)A'' for <span class="hlt">Fe</span>3S4, (6)A'' for <span class="hlt">Fe</span>3S4(-), (1)A1 for <span class="hlt">Fe</span>4S4, and (1)A2 for <span class="hlt">Fe</span>4S4(-). In addition, <span class="hlt">Fe</span>2S2, <span class="hlt">Fe</span>3S4, <span class="hlt">Fe</span>3S4(-), <span class="hlt">Fe</span>4S4, and <span class="hlt">Fe</span>4S4(-) are antiferromagnetic at the B3LYP/6-311+G* level. The magnetic properties are discussed on the basis of natural bond orbital analysis. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27018641','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27018641"><span>Molprobity's ultimate rotamer-library distributions for <span class="hlt">model</span> <span class="hlt">validation</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hintze, Bradley J; Lewis, Steven M; Richardson, Jane S; Richardson, David C</p> <p>2016-09-01</p> <p>Here we describe the updated MolProbity rotamer-library distributions derived from an order-of-magnitude larger and more stringently quality-filtered dataset of about 8000 (vs. 500) protein chains, and we explain the resulting changes and improvements to <span class="hlt">model</span> <span class="hlt">validation</span> as seen by users. To include only side-chains with satisfactory justification for their given conformation, we added residue-specific filters for electron-density value and <span class="hlt">model</span>-to-density fit. The combined new protocol retains a million residues of data, while cleaning up false-positive noise in the multi- χ datapoint distributions. It enables unambiguous characterization of conformational clusters nearly 1000-fold less frequent than the most common ones. We describe examples of local interactions that favor these rare conformations, including the role of authentic covalent bond-angle deviations in enabling presumably strained side-chain conformations. Further, along with favored and outlier, an allowed category (0.3-2.0% occurrence in reference data) has been added, analogous to Ramachandran <span class="hlt">validation</span> categories. The new rotamer distributions are used for current rotamer <span class="hlt">validation</span> in MolProbity and PHENIX, and for rotamer choice in PHENIX <span class="hlt">model</span>-building and refinement. The multi-dimensional χ distributions and Top8000 reference dataset are freely available on GitHub. These rotamers are termed "ultimate" because data sampling and quality are now fully adequate for this task, and also because we believe the future of conformational <span class="hlt">validation</span> should integrate side-chain with backbone criteria. Proteins 2016; 84:1177-1189. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24668605','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24668605"><span>FDA 2011 process <span class="hlt">validation</span> guidance: lifecycle compliance <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campbell, Cliff</p> <p>2014-01-01</p> <p>This article has been written as a contribution to the industry's efforts in migrating from a document-driven to a data-driven compliance mindset. A combination of target product profile, control engineering, and general sum principle techniques is presented as the basis of a simple but scalable lifecycle compliance <span class="hlt">model</span> in support of modernized process <span class="hlt">validation</span>. Unit operations and significant variables occupy pole position within the <span class="hlt">model</span>, documentation requirements being treated as a derivative or consequence of the <span class="hlt">modeling</span> process. The quality system is repositioned as a subordinate of system quality, this being defined as the integral of related "system qualities". The article represents a structured interpretation of the U.S. Food and Drug Administration's 2011 Guidance for Industry on Process <span class="hlt">Validation</span> and is based on the author's educational background and his manufacturing/consulting experience in the <span class="hlt">validation</span> field. The U.S. Food and Drug Administration's Guidance for Industry on Process <span class="hlt">Validation</span> (2011) provides a wide-ranging and rigorous outline of compliant drug manufacturing requirements relative to its 20(th) century predecessor (1987). Its declared focus is patient safety, and it identifies three inter-related (and obvious) stages of the compliance lifecycle. Firstly, processes must be designed, both from a technical and quality perspective. Secondly, processes must be qualified, providing evidence that the manufacturing facility is fully "roadworthy" and fit for its intended purpose. Thirdly, processes must be verified, meaning that commercial batches must be monitored to ensure that processes remain in a state of control throughout their lifetime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED442525.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED442525.pdf"><span>Institutional Effectiveness: A <span class="hlt">Model</span> for Planning, Assessment & <span class="hlt">Validation</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Truckee Meadows Community Coll., Sparks, NV.</p> <p></p> <p>The report presents Truckee Meadows Community College's (Colorado) <span class="hlt">model</span> for assessing institutional effectiveness and <span class="hlt">validating</span> the College's mission and vision, and the strategic plan for carrying out the institutional effectiveness <span class="hlt">model</span>. It also outlines strategic goals for the years 1999-2001. From the system-wide directive that education…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.7958V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.7958V"><span>Soil process <span class="hlt">modelling</span> in CZO research: gains in data harmonisation and <span class="hlt">model</span> <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Gaans, Pauline; Andrianaki, Maria; Kobierska, Florian; Kram, Pavel; Lamacova, Anna; Lair, Georg; Nikolaidis, Nikos; Duffy, Chris; Regelink, Inge; van Leeuwen, Jeroen P.; de Ruiter, Peter</p> <p>2014-05-01</p> <p>Various soil process <span class="hlt">models</span> were applied to four European Critical Zone observatories (CZOs), the core research sites of the FP7 project SoilTrEC: the Damma glacier forefield (CH), a set of three forested catchments on geochemically contrasing bedrocks in the Slavkov Forest (CZ), a chronosequence of soils in the former floodplain of the Danube of Fuchsenbigl/Marchfeld (AT), and the Koiliaris catchments in the north-western part of Crete, (GR). The aim of the <span class="hlt">modelling</span> exercises was to apply and test soil process <span class="hlt">models</span> with data from the CZOs for calibration/<span class="hlt">validation</span>, identify potential limits to the application scope of the <span class="hlt">models</span>, interpret soil state and soil functions at key stages of the soil life cycle, represented by the four SoilTrEC CZOs, contribute towards harmonisation of data and data acquisition. The <span class="hlt">models</span> identified as specifically relevant were: The Penn State Integrated Hydrologic <span class="hlt">Model</span> (PIHM), a fully coupled, multiprocess, multi-scale hydrologic <span class="hlt">model</span>, to get a better understanding of water flow and pathways, The Soil and Water Assessment Tool (SWAT), a deterministic, continuous time (daily time step) basin scale <span class="hlt">model</span>, to evaluate the impact of soil management practices, The Rothamsted Carbon <span class="hlt">model</span> (Roth-C) to simulate organic carbon turnover and the Carbon, Aggregation, and Structure Turnover (CAST) <span class="hlt">model</span> to include the role of soil aggregates in carbon dynamics, The Ligand Charge Distribution (LCD) <span class="hlt">model</span>, to understand the interaction between organic matter and oxide surfaces in soil aggregate formation, and The Terrestrial Ecology <span class="hlt">Model</span> (TEM) to obtain insight into the link between foodweb structure and carbon and nutrient turnover. With some exceptions all <span class="hlt">models</span> were applied to all four CZOs. The need for specific <span class="hlt">model</span> input contributed largely to data harmonisation. The comparisons between the CZOs turned out to be of great value for understanding the strength and limitations of the <span class="hlt">models</span>, as well as the differences in soil conditions</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28488864','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28488864"><span>Temperature and Pressure Dependences of the Reactions of <span class="hlt">Fe</span>+ with Methyl Halides CH3X (X = Cl, Br, I): Experiments and Kinetic <span class="hlt">Modeling</span> Results.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ard, Shaun G; Shuman, Nicholas S; Martinez, Oscar; Keyes, Nicholas R; Viggiano, Albert A; Guo, Hua; Troe, Jürgen</p> <p>2017-06-01</p> <p>The pressure and temperature dependences of the reactions of <span class="hlt">Fe</span> + with methyl halides CH 3 X (X = Cl, Br, I) in He were measured in a selected ion flow tube over the ranges 0.4 to 1.2 Torr and 300-600 K. <span class="hlt">Fe</span>X + was observed for all three halides and <span class="hlt">Fe</span>CH 3 + was observed for the CH 3 I reaction. <span class="hlt">Fe</span>CH 3 X + adducts (for all X) were detected in all reactions. The results were interpreted assuming two-state reactivity with spin-inversions between sextet and quartet potentials. Kinetic <span class="hlt">modeling</span> allowed for a quantitative representation of the experiments and for extrapolation to conditions outside the experimentally accessible range. The <span class="hlt">modeling</span> required quantum-chemical calculations of molecular parameters and detailed accounting of angular momentum effects. The results show that the <span class="hlt">Fe</span>X + products come via an insertion mechanism, while the <span class="hlt">Fe</span>CH 3 + can be produced from either insertion or S N 2 mechanisms, but the latter we conclude is unlikely at thermal energies. A statistical <span class="hlt">modeling</span> cannot reproduce the competition between the bimolecular pathways in the CH 3 I reaction, indicating that some more direct process must be important.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMS...182...67S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMS...182...67S"><span>Impact on the <span class="hlt">Fe</span> redox cycling of organic ligands released by Synechococcus PCC 7002, under different iron fertilization scenarios. <span class="hlt">Modeling</span> approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Samperio-Ramos, Guillermo; González-Dávila, Melchor; Santana-Casiano, J. Magdalena</p> <p>2018-06-01</p> <p>The kinetics of <span class="hlt">Fe</span> redox transformations are of crucial importance in determining the bioavailability of iron, due to inorganic <span class="hlt">Fe</span>(II) and <span class="hlt">Fe</span> weakly organic complexes being the most easily assimilated species by phytoplankton. The role played by the natural organic ligands excreted by the cyanobacteria Synecococcus PCC 7002 on the iron redox chemistry was studied at different stages of growth, considering changes in the organic exudation of the cyanobacteria, associated with growth under two different scenarios of iron availability. The oxidation/reduction processes of iron were studied at nanomolar levels and under different physicochemical conditions of pH (7.2- 8.2), temperature (5- 35 °C) and salinity (10- 37). The presence of natural organic exudates of Synechococcus affected the redox behavior of iron. A pH-dependent and photo-induced <span class="hlt">Fe</span>(III) reduction process was detected in the presence of exudates produced under <span class="hlt">Fe</span>-Low conditions. Photolytic reactions also modified the reactivity of those exudates with respect to <span class="hlt">Fe</span>(II), increasing its lifetime in seawater. Without light mediated processes, organic ligands excreted under iron deficient conditions intensified the <span class="hlt">Fe</span>(II) oxidation at pH < 7.5. The organic exudates released under High-<span class="hlt">Fe</span> conditions retarded the <span class="hlt">Fe</span>(II) oxidation rate, as a function of DOC produced. The changes in the apparent oxidation rate were fitted to polynomial functions for both of the <span class="hlt">Fe</span>-scenarios considered. A kinetic <span class="hlt">modeling</span> approach to describe the speciation and the contribution of individual <span class="hlt">Fe</span>(II) species to the overall oxidation rate was applied, considering the experimental data and delimiting the equilibrium and redox constants between iron and the major ligands present in solution. Two organic type ligands for the exudates of Synechococcus PCC 7002, with different iron-chelation properties were included in the <span class="hlt">model</span>. The <span class="hlt">Fe</span>(II) speciation was radically affected when organic ligands were considered. The individual</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013MMTB...44..820C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013MMTB...44..820C"><span>Viscosity of SiO2-"<span class="hlt">Fe</span>O"-Al2O3 System in Equilibrium with Metallic <span class="hlt">Fe</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Mao; Raghunath, Sreekanth; Zhao, Baojun</p> <p>2013-08-01</p> <p>The present study delivered the measurements of viscosities in SiO2-"<span class="hlt">Fe</span>O"-Al2O3 system in equilibrium with metallic <span class="hlt">Fe</span>. The rotational spindle technique was used in the measurements at the temperature range of 1473 K to 1773 K (1200 °C to 1500 °C). Molybdenum crucibles and spindles were employed in all measurements. The <span class="hlt">Fe</span> saturation condition was maintained by an iron plate placed at the bottom of the crucible. The equilibrium compositions of the slags were measured by EPMA after the viscosity measurements. The effect of up to 20 mol. pct Al2O3 on the viscosity of the SiO2-"<span class="hlt">Fe</span>O" slag was investigated. The "charge compensation effect" of the Al2O3 and <span class="hlt">Fe</span>O association has been discussed. The modified quasi-chemical viscosity <span class="hlt">model</span> has been optimized in the SiO2-"<span class="hlt">Fe</span>O"-Al2O3 system in equilibrium with metallic <span class="hlt">Fe</span> to describe the viscosity measurements of the present study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22577839','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22577839"><span><span class="hlt">Fe</span> atom exchange between aqueous <span class="hlt">Fe</span>2+ and magnetite.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gorski, Christopher A; Handler, Robert M; Beard, Brian L; Pasakarnis, Timothy; Johnson, Clark M; Scherer, Michelle M</p> <p>2012-11-20</p> <p>The reaction between magnetite and aqueous <span class="hlt">Fe</span>(2+) has been extensively studied due to its role in contaminant reduction, trace-metal sequestration, and microbial respiration. Previous work has demonstrated that the reaction of <span class="hlt">Fe</span>(2+) with magnetite (<span class="hlt">Fe</span>(3)O(4)) results in the structural incorporation of <span class="hlt">Fe</span>(2+) and an increase in the bulk <span class="hlt">Fe</span>(2+) content of magnetite. It is unclear, however, whether significant <span class="hlt">Fe</span> atom exchange occurs between magnetite and aqueous <span class="hlt">Fe</span>(2+), as has been observed for other <span class="hlt">Fe</span> oxides. Here, we measured the extent of <span class="hlt">Fe</span> atom exchange between aqueous <span class="hlt">Fe</span>(2+) and magnetite by reacting isotopically "normal" magnetite with (57)<span class="hlt">Fe</span>-enriched aqueous <span class="hlt">Fe</span>(2+). The extent of <span class="hlt">Fe</span> atom exchange between magnetite and aqueous <span class="hlt">Fe</span>(2+) was significant (54-71%), and went well beyond the amount of <span class="hlt">Fe</span> atoms found at the near surface. Mössbauer spectroscopy of magnetite reacted with (56)<span class="hlt">Fe</span>(2+) indicate that no preferential exchange of octahedral or tetrahedral sites occurred. Exchange experiments conducted with Co-ferrite (Co(2+)<span class="hlt">Fe</span>(2)(3+)O(4)) showed little impact of Co substitution on the rate or extent of atom exchange. Bulk electron conduction, as previously invoked to explain <span class="hlt">Fe</span> atom exchange in goethite, is a possible mechanism, but if it is occurring, conduction does not appear to be the rate-limiting step. The lack of significant impact of Co substitution on the kinetics of <span class="hlt">Fe</span> atom exchange, and the relatively high diffusion coefficients reported for magnetite suggest that for magnetite, unlike goethite, <span class="hlt">Fe</span> atom diffusion is a plausible mechanism to explain the rapid rates of <span class="hlt">Fe</span> atom exchange in magnetite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26833355','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26833355"><span>Anisotropic Multishell Analytical <span class="hlt">Modeling</span> of an Intervertebral Disk Subjected to Axial Compression.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Demers, Sébastien; Nadeau, Sylvie; Bouzid, Abdel-Hakim</p> <p>2016-04-01</p> <p>Studies on intervertebral disk (IVD) response to various loads and postures are essential to understand disk's mechanical functions and to suggest preventive and corrective actions in the workplace. The experimental and finite-element (<span class="hlt">FE</span>) approaches are well-suited for these studies, but <span class="hlt">validating</span> their findings is difficult, partly due to the lack of alternative methods. Analytical <span class="hlt">modeling</span> could allow methodological triangulation and help <span class="hlt">validation</span> of <span class="hlt">FE</span> <span class="hlt">models</span>. This paper presents an analytical method based on thin-shell, beam-on-elastic-foundation and composite materials theories to evaluate the stresses in the anulus fibrosus (AF) of an axisymmetric disk composed of multiple thin lamellae. Large deformations of the soft tissues are accounted for using an iterative method and the anisotropic material properties are derived from a published biaxial experiment. The results are compared to those obtained by <span class="hlt">FE</span> <span class="hlt">modeling</span>. The results demonstrate the capability of the analytical <span class="hlt">model</span> to evaluate the stresses at any location of the simplified AF. It also demonstrates that anisotropy reduces stresses in the lamellae. This novel <span class="hlt">model</span> is a preliminary step in developing valuable analytical <span class="hlt">models</span> of IVDs, and represents a distinctive groundwork that is able to sustain future refinements. This paper suggests important features that may be included to improve <span class="hlt">model</span> realism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Project+AND+power+AND+factor&id=EJ1070799','ERIC'); return false;" href="https://eric.ed.gov/?q=Project+AND+power+AND+factor&id=EJ1070799"><span><span class="hlt">Validating</span> a Technology Enhanced Student-Centered Learning <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kang, Myunghee; Hahn, Jungsun; Chung, Warren</p> <p>2015-01-01</p> <p>The Technology Enhanced Student Centered Learning (TESCL) <span class="hlt">Model</span> in this study presents the core factors that ensure the quality of learning in a technology-supported environment. Although the <span class="hlt">model</span> was conceptually constructed using a student-centered learning framework and drawing upon previous studies, it should be <span class="hlt">validated</span> through real-world…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4165230','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4165230"><span>A comprehensive computational <span class="hlt">model</span> of sound transmission through the porcine lung</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dai, Zoujun; Peng, Ying; Henry, Brian M.; Mansy, Hansen A.; Sandler, Richard H.; Royston, Thomas J.</p> <p>2014-01-01</p> <p>A comprehensive computational simulation <span class="hlt">model</span> of sound transmission through the porcine lung is introduced and experimentally evaluated. This “subject-specific” <span class="hlt">model</span> utilizes parenchymal and major airway geometry derived from x-ray CT images. The lung parenchyma is <span class="hlt">modeled</span> as a poroviscoelastic material using Biot theory. A finite element (<span class="hlt">FE</span>) mesh of the lung that includes airway detail is created and used in comsol <span class="hlt">FE</span> software to simulate the vibroacoustic response of the lung to sound input at the trachea. The <span class="hlt">FE</span> simulation <span class="hlt">model</span> is <span class="hlt">validated</span> by comparing simulation results to experimental measurements using scanning laser Doppler vibrometry on the surface of an excised, preserved lung. The <span class="hlt">FE</span> <span class="hlt">model</span> can also be used to calculate and visualize vibroacoustic pressure and motion inside the lung and its airways caused by the acoustic input. The effect of diffuse lung fibrosis and of a local tumor on the lung acoustic response is simulated and visualized using the <span class="hlt">FE</span> <span class="hlt">model</span>. In the future, this type of visualization can be compared and matched with experimentally obtained elastographic images to better quantify regional lung material properties to noninvasively diagnose and stage disease and response to treatment. PMID:25190415</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25190415','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25190415"><span>A comprehensive computational <span class="hlt">model</span> of sound transmission through the porcine lung.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dai, Zoujun; Peng, Ying; Henry, Brian M; Mansy, Hansen A; Sandler, Richard H; Royston, Thomas J</p> <p>2014-09-01</p> <p>A comprehensive computational simulation <span class="hlt">model</span> of sound transmission through the porcine lung is introduced and experimentally evaluated. This "subject-specific" <span class="hlt">model</span> utilizes parenchymal and major airway geometry derived from x-ray CT images. The lung parenchyma is <span class="hlt">modeled</span> as a poroviscoelastic material using Biot theory. A finite element (<span class="hlt">FE</span>) mesh of the lung that includes airway detail is created and used in comsol <span class="hlt">FE</span> software to simulate the vibroacoustic response of the lung to sound input at the trachea. The <span class="hlt">FE</span> simulation <span class="hlt">model</span> is <span class="hlt">validated</span> by comparing simulation results to experimental measurements using scanning laser Doppler vibrometry on the surface of an excised, preserved lung. The <span class="hlt">FE</span> <span class="hlt">model</span> can also be used to calculate and visualize vibroacoustic pressure and motion inside the lung and its airways caused by the acoustic input. The effect of diffuse lung fibrosis and of a local tumor on the lung acoustic response is simulated and visualized using the <span class="hlt">FE</span> <span class="hlt">model</span>. In the future, this type of visualization can be compared and matched with experimentally obtained elastographic images to better quantify regional lung material properties to noninvasively diagnose and stage disease and response to treatment.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040086466','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040086466"><span>Finite Element <span class="hlt">Model</span> Development and <span class="hlt">Validation</span> for Aircraft Fuselage Structures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buehrle, Ralph D.; Fleming, Gary A.; Pappa, Richard S.; Grosveld, Ferdinand W.</p> <p>2000-01-01</p> <p>The ability to extend the <span class="hlt">valid</span> frequency range for finite element based structural dynamic predictions using detailed <span class="hlt">models</span> of the structural components and attachment interfaces is examined for several stiffened aircraft fuselage structures. This extended dynamic prediction capability is needed for the integration of mid-frequency noise control technology. Beam, plate and solid element <span class="hlt">models</span> of the stiffener components are evaluated. Attachment <span class="hlt">models</span> between the stiffener and panel skin range from a line along the rivets of the physical structure to a constraint over the entire contact surface. The finite element <span class="hlt">models</span> are <span class="hlt">validated</span> using experimental modal analysis results. The increased frequency range results in a corresponding increase in the number of modes, modal density and spatial resolution requirements. In this study, conventional modal tests using accelerometers are complemented with Scanning Laser Doppler Velocimetry and Electro-Optic Holography measurements to further resolve the spatial response characteristics. Whenever possible, component and subassembly modal tests are used to <span class="hlt">validate</span> the finite element <span class="hlt">models</span> at lower levels of assembly. Normal mode predictions for different finite element representations of components and assemblies are compared with experimental results to assess the most accurate techniques for <span class="hlt">modeling</span> aircraft fuselage type structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70159278','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70159278"><span>Monitoring, field experiments, and geochemical <span class="hlt">modeling</span> of <span class="hlt">Fe</span>(II) oxidation kinetics in a stream dominated by net-alkaline coal-mine drainage, Pennsylvania, USA</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cravotta, Charles A.</p> <p>2015-01-01</p> <p>Watershed-scale monitoring, field aeration experiments, and geochemical equilibrium and kinetic <span class="hlt">modeling</span> were conducted to evaluate interdependent changes in pH, dissolved CO2, O2, and <span class="hlt">Fe</span>(II) concentrations that typically take place downstream of net-alkaline, circumneutral coal-mine drainage (CMD) outfalls and during aerobic treatment of such CMD. The kinetic <span class="hlt">modeling</span> approach, using PHREEQC, accurately simulates observed variations in pH, <span class="hlt">Fe</span>(II) oxidation, alkalinity consumption, and associated dissolved gas concentrations during transport downstream of the CMD outfalls (natural attenuation) and during 6-h batch aeration tests on the CMD using bubble diffusers (enhanced attenuation). The batch aeration experiments demonstrated that aeration promoted CO2 outgassing, thereby increasing pH and the rate of <span class="hlt">Fe</span>(II) oxidation. The rate of <span class="hlt">Fe</span>(II) oxidation was accurately estimated by the abiotic homogeneous oxidation rate law −d[<span class="hlt">Fe</span>(II)]/dt = k1·[O2]·[H+]−2·[<span class="hlt">Fe</span>(II)] that indicates an increase in pH by 1 unit at pH 5–8 and at constant dissolved O2 (DO) concentration results in a 100-fold increase in the rate of <span class="hlt">Fe</span>(II) oxidation. Adjusting for sample temperature, a narrow range of values for the apparent homogeneous <span class="hlt">Fe</span>(II) oxidation rate constant (k1′) of 0.5–1.7 times the reference value of k1 = 3 × 10−12 mol/L/min (for pH 5–8 and 20 °C), reported by Stumm and Morgan (1996), was indicated by the calibrated <span class="hlt">models</span> for the 5-km stream reach below the CMD outfalls and the aerated CMD. The rates of CO2 outgassing and O2ingassing in the <span class="hlt">model</span> were estimated with first-order asymptotic functions, whereby the driving force is the gradient of the dissolved gas concentration relative to equilibrium with the ambient atmosphere. Although the progressive increase in DO concentration to saturation could be accurately <span class="hlt">modeled</span> as a kinetic function for the conditions evaluated, the simulation of DO as an instantaneous equilibrium process did not affect the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JNuM..412..106P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JNuM..412..106P"><span>Stability and mobility of Cu-vacancy clusters in <span class="hlt">Fe</span>-Cu alloys: A computational study based on the use of artificial neural networks for energy barrier calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pascuet, M. I.; Castin, N.; Becquart, C. S.; Malerba, L.</p> <p>2011-05-01</p> <p>An atomistic kinetic Monte Carlo (AKMC) method has been applied to study the stability and mobility of copper-vacancy clusters in <span class="hlt">Fe</span>. This information, which cannot be obtained directly from experimental measurements, is needed to parameterise <span class="hlt">models</span> describing the nanostructure evolution under irradiation of <span class="hlt">Fe</span> alloys (e.g. <span class="hlt">model</span> alloys for reactor pressure vessel steels). The physical reliability of the AKMC method has been improved by employing artificial intelligence techniques for the regression of the activation energies required by the <span class="hlt">model</span> as input. These energies are calculated allowing for the effects of local chemistry and relaxation, using an interatomic potential fitted to reproduce them as accurately as possible and the nudged-elastic-band method. The <span class="hlt">model</span> <span class="hlt">validation</span> was based on comparison with available ab initio calculations for verification of the used cohesive <span class="hlt">model</span>, as well as with other <span class="hlt">models</span> and theories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeCoA.225..116W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeCoA.225..116W"><span>Kinetics of <span class="hlt">Fe</span>II-polyaminocarboxylate oxidation by molecular oxygen</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilson, Jessica M.; Farley, Kevin J.; Carbonaro, Richard F.</p> <p>2018-03-01</p> <p>Complexation of iron by naturally-occurring and synthetic organic ligands has a large effect on iron oxidation and reduction rates which in turn affect the aqueous geochemistry of many other chemical constituents. In this study, the kinetics of <span class="hlt">Fe</span>II oxidation in the presence of the polyaminocarboxylate synthetic chelating agents ethylene glycol tetraacetic acid (EGTA) and trimethylenediamine-N,N,N‧,N‧-tetraacetic acid (TMDTA) was investigated over the pH range 5.50-8.53. Batch oxidation experiments in the presence of molecular oxygen were conducted using a 2:1 M concentration ratio of polyaminocarboxylate (ligand, L) to <span class="hlt">Fe</span>II. The experimental data resembled first order kinetics for the oxidation of <span class="hlt">Fe</span>II-L to <span class="hlt">Fe</span>III-L and observed rate constants at pH 6.0 were comparable to rate constants for the oxidation of inorganic <span class="hlt">Fe</span>II. Similar to other structurally-similar <span class="hlt">Fe</span>II-polyaminocarboxylate complexes, oxidation rates of <span class="hlt">Fe</span>II-EGTA and <span class="hlt">Fe</span>II-TMDTA decrease with increasing pH, which is the opposite trend for the oxidation of <span class="hlt">Fe</span>II complexed with inorganic ligands. However, the oxidation rates of <span class="hlt">Fe</span>II complexed with EGTA and TMDTA were considerably lower (4-5 orders of magnitude) than <span class="hlt">Fe</span>II complexed to ethylenediaminetetraacetic acid (EDTA). The distinguishing feature of the slower-reacting complexes is that they have a longer backbone between diamine functional groups. An analytical equilibrium <span class="hlt">model</span> was developed to determine the contributions of the species <span class="hlt">Fe</span>IIL2- and <span class="hlt">Fe</span>II(H)L- to the overall oxidation rate of <span class="hlt">Fe</span>II-L. Application of this <span class="hlt">model</span> indicated that the protonated <span class="hlt">Fe</span>II(H)L species are more than three orders of magnitude more reactive than <span class="hlt">Fe</span>IIL2-. These rate constants were used in a coupled kinetic equilibrium numerical <span class="hlt">model</span> where the ligand to iron ratio (TOTL:TOTFe) and pH were varied to evaluate the effect on the <span class="hlt">Fe</span>II oxidation rate. Overall, increasing TOTL:TOTFe for EGTA and TMDTA enhances <span class="hlt">Fe</span>II oxidation rates at lower pH and inhibits <span class="hlt">Fe</span>II oxidation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22310658-controllable-exchange-bias-fe-metamagnetic-ferh-bilayers','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22310658-controllable-exchange-bias-fe-metamagnetic-ferh-bilayers"><span>Controllable exchange bias in <span class="hlt">Fe</span>/metamagnetic <span class="hlt">Fe</span>Rh bilayers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Suzuki, Ippei; Hamasaki, Yosuke; Itoh, Mitsuru</p> <p>2014-10-27</p> <p>We report the studies of tuning the exchange bias at ferromagnetic <span class="hlt">Fe</span>/metamagnetic <span class="hlt">Fe</span>Rh bilayer interfaces. <span class="hlt">Fe/Fe</span>Rh(111) bilayers show exchange bias in the antiferromagnetic state of <span class="hlt">Fe</span>Rh while no exchange bias occurs at <span class="hlt">Fe/Fe</span>Rh(001) interface. The contrasting results are attributed to the spin configurations of <span class="hlt">Fe</span>Rh at the interface, i.e., the uncompensated ferromagnetic spin configuration of <span class="hlt">Fe</span>Rh appears exclusively for (111) orientation. The exchange bias disappears as the bilayers are warmed above the antiferromagnetic-ferromagnetic transition temperature. The direction of the exchange bias for <span class="hlt">Fe/Fe</span>Rh(111) is also found to be perpendicular to the cooling-field direction, in contrast to the commonly observed directionmore » of exchange bias for ferromagnetic/antiferromagnetic interfaces. In view of these results, the exchange bias in <span class="hlt">Fe/Fe</span>Rh bilayers with the (111) crystallographic orientation should be useful for the design of rapid writing technology for magnetic information devices.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26488197','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26488197"><span>[Ni<span class="hlt">Fe</span>Se]-hydrogenase chemistry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wombwell, Claire; Caputo, Christine A; Reisner, Erwin</p> <p>2015-11-17</p> <p>The development of technology for the inexpensive generation of the renewable energy vector H2 through water splitting is of immediate economic, ecological, and humanitarian interest. Recent interest in hydrogenases has been fueled by their exceptionally high catalytic rates for H2 production at a marginal overpotential, which is presently only matched by the nonscalable noble metal platinum. The mechanistic understanding of hydrogenase function guides the design of synthetic catalysts, and selection of a suitable hydrogenase enables direct applications in electro- and photocatalysis. [<span class="hlt">FeFe</span>]-hydrogenases display excellent H2 evolution activity, but they are irreversibly damaged upon exposure to O2, which currently prevents their use in full water splitting systems. O2-tolerant [Ni<span class="hlt">Fe</span>]-hydrogenases are known, but they are typically strongly biased toward H2 oxidation, while H2 production by [Ni<span class="hlt">Fe</span>]-hydrogenases is often product (H2) inhibited. [Ni<span class="hlt">Fe</span>Se]-hydrogenases are a subclass of [Ni<span class="hlt">Fe</span>]-hydrogenases with a selenocysteine residue coordinated to the active site nickel center in place of a cysteine. They exhibit a combination of unique properties that are highly advantageous for applications in water splitting compared with other hydrogenases. They display a high H2 evolution rate with marginal inhibition by H2 and tolerance to O2. [Ni<span class="hlt">Fe</span>Se]-hydrogenases are therefore one of the most active molecular H2 evolution catalysts applicable in water splitting. Herein, we summarize our recent progress in exploring the unique chemistry of [Ni<span class="hlt">Fe</span>Se]-hydrogenases through biomimetic <span class="hlt">model</span> chemistry and the chemistry with [Ni<span class="hlt">Fe</span>Se]-hydrogenases in semiartificial photosynthetic systems. We gain perspective from the structural, spectroscopic, and electrochemical properties of the [Ni<span class="hlt">Fe</span>Se]-hydrogenases and compare them with the chemistry of synthetic <span class="hlt">models</span> of this hydrogenase active site. Our synthetic <span class="hlt">models</span> give insight into the effects on the electronic properties and reactivity of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5662183','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5662183"><span>Ethylenediamine grafted to graphene oxide@<span class="hlt">Fe</span>3O4 for chromium(VI) decontamination: Performance, <span class="hlt">modelling</span>, and fractional factorial design</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xu, Jiawen; Wu, Cuiyu; Deng, Jianbin; Liao, Wenwei; Ling, Yuxiang; Yang, Yuanxiu; Zhao, Yina; Zhao, Yunlin; Hu, Xi; Wang, Hui; Liu, Yunguo</p> <p>2017-01-01</p> <p>A method for grafting ethylenediamine to a magnetic graphene oxide composite (EDA-GO@<span class="hlt">Fe</span>3O4) was developed for Cr(VI) decontamination. The physicochemical properties of EDA-GO@<span class="hlt">Fe</span>3O4 were characterized using HRTEM, EDS, FT-IR, TG-DSC, and XPS. The effects of pH, sorbent dose, foreign anions, time, Cr(VI) concentration, and temperature on decontamination process were studied. The solution pH can largely affect the decontamination process. The pseudo-second-order <span class="hlt">model</span> is suitable for being applied to fit the adsorption processes of Cr(VI) with GO@<span class="hlt">Fe</span>3O4 and EDA-GO@<span class="hlt">Fe</span>3O4. The intra-particle diffusion is not the rate-controlling step. Isotherm experimental data can be described using the Freundlich <span class="hlt">model</span>. The effects of multiple factors on the Cr(VI) decontamination was investigated by a 25−1 fractional factorial design (FFD). The adsorption process can significantly be affected by the main effects of A (pH), B (Cr(VI) concentration), and E (Adsorbent dose). The combined factors of AB (pH × Cr(VI) concentration), AE (pH × Adsorbent dose), and BC (Cr(VI) concentration × Temperature) had larger effects than other factors on Cr(VI) removal. These results indicated that EDA-GO@<span class="hlt">Fe</span>3O4 is a potential and suitable candidate for treatment of heavy metal wastewater. PMID:29084287</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27690423','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27690423"><span>Effectiveness of <span class="hlt">Fe</span>EDDHA, <span class="hlt">Fe</span>EDDHMA, and <span class="hlt">Fe</span>HBED in Preventing Iron-Deficiency Chlorosis in Soybean.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bin, Levi M; Weng, Liping; Bugter, Marcel H J</p> <p>2016-11-09</p> <p>The performance of <span class="hlt">Fe</span>HBED in preventing <span class="hlt">Fe</span> deficiency chlorosis in soybean (Glycine max (L.) Merr.) in comparison to <span class="hlt">Fe</span>EDDHA and <span class="hlt">Fe</span>EDDHMA was studied, as well as the importance of the ortho-ortho and ortho-para/rest isomers in defining the performance. To this end, chlorophyll production (SPAD), plant dry matter yield, and the mass fractions of important mineral elements in the plant were quantified in a greenhouse pot experiment. All three <span class="hlt">Fe</span> chelates increased SPAD index and dry matter yield compared to the control. The effect of <span class="hlt">Fe</span>HBED on chlorophyll production was visible over a longer time span than that of <span class="hlt">Fe</span>EDDHA and <span class="hlt">Fe</span>EDDHMA. Additionally, <span class="hlt">Fe</span>HBED did not suppress Mn uptake as much as the other <span class="hlt">Fe</span> chelates. Compared to the other <span class="hlt">Fe</span> chelates, total <span class="hlt">Fe</span> content in the young leaves was lower in the <span class="hlt">Fe</span>HBED treatment; however, total <span class="hlt">Fe</span> content was not directly related to chlorophyll production and biomass yield. For each chelate, the ortho-ortho isomer was found to be more effective than the other isomers evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4510703','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4510703"><span>Molybdenum L-Edge XAS Spectra of Mo<span class="hlt">Fe</span> Nitrogenase</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bjornsson, Ragnar; Delgado-Jaime, Mario U; Lima, Frederico A; Sippel, Daniel; Schlesier, Julia; Weyhermüller, Thomas; Einsle, Oliver; Neese, Frank; DeBeer, Serena</p> <p>2015-01-01</p> <p>A molybdenum L-edge X-ray absorption spectroscopy (XAS) study is presented for native and oxidized Mo<span class="hlt">Fe</span> protein of nitrogenase as well as Mo-<span class="hlt">Fe</span> <span class="hlt">model</span> compounds. Recently collected data on Mo<span class="hlt">Fe</span> protein (in oxidized and reduced forms) is compared to previously published Mo XAS data on the isolated <span class="hlt">Fe</span>Mo cofactor in NMF solution and put in context of the recent Mo K-edge XAS study, which showed a MoIII assignment for the molybdenum atom in <span class="hlt">Fe</span>Moco. The L3-edge data are interpreted within a simple ligand-field <span class="hlt">model</span>, from which a time-dependent density functional theory (TDDFT) approach is proposed as a way to provide further insights into the analysis of the molybdenum L3-edges. The calculated results reproduce well the relative spectral trends that are observed experimentally. Ultimately, these results give further support for the MoIII assignment in protein-bound <span class="hlt">Fe</span>Moco, as well as isolated <span class="hlt">Fe</span>Moco. PMID:26213424</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28865348','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28865348"><span>Prediction of muscle activation for an eye movement with finite element <span class="hlt">modeling</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karami, Abbas; Eghtesad, Mohammad; Haghpanah, Seyyed Arash</p> <p>2017-10-01</p> <p>In this paper, a 3D finite element (<span class="hlt">FE</span>) <span class="hlt">modeling</span> is employed in order to predict extraocular muscles' activation and investigate force coordination in various motions of the eye orbit. A continuum constitutive hyperelastic <span class="hlt">model</span> is employed for material description in dynamic <span class="hlt">modeling</span> of the extraocular muscles (EOMs). Two significant features of this <span class="hlt">model</span> are accurate mass <span class="hlt">modeling</span> with <span class="hlt">FE</span> method and stimulating EOMs for motion through muscle activation parameter. In order to <span class="hlt">validate</span> the eye <span class="hlt">model</span>, a forward dynamics simulation of the eye motion is carried out by variation of the muscle activation. Furthermore, to realize muscle activation prediction in various eye motions, two different tracking-based inverse controllers are proposed. The performance of these two inverse controllers is investigated according to their resulted muscle force magnitude and muscle force coordination. The simulation results are compared with the available experimental data and the well-known existing neurological laws. The comparison authenticates both the <span class="hlt">validation</span> and the prediction results. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMEP...25.4089J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMEP...25.4089J"><span>Thermal <span class="hlt">Modeling</span> of Al-Al and Al-Steel Friction Stir Spot Welding</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jedrasiak, P.; Shercliff, H. R.; Reilly, A.; McShane, G. J.; Chen, Y. C.; Wang, L.; Robson, J.; Prangnell, P.</p> <p>2016-09-01</p> <p>This paper presents a finite element thermal <span class="hlt">model</span> for similar and dissimilar alloy friction stir spot welding (FSSW). The <span class="hlt">model</span> is calibrated and <span class="hlt">validated</span> using instrumented lap joints in Al-Al and Al-<span class="hlt">Fe</span> automotive sheet alloys. The <span class="hlt">model</span> successfully predicts the thermal histories for a range of process conditions. The resulting temperature histories are used to predict the growth of intermetallic phases at the interface in Al-<span class="hlt">Fe</span> welds. Temperature predictions were used to study the evolution of hardness of a precipitation-hardened aluminum alloy during post-weld aging after FSSW.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5818422','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5818422"><span><span class="hlt">Validation</span> and Trustworthiness of Multiscale <span class="hlt">Models</span> of Cardiac Electrophysiology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pathmanathan, Pras; Gray, Richard A.</p> <p>2018-01-01</p> <p>Computational <span class="hlt">models</span> of cardiac electrophysiology have a long history in basic science applications and device design and evaluation, but have significant potential for clinical applications in all areas of cardiovascular medicine, including functional imaging and mapping, drug safety evaluation, disease diagnosis, patient selection, and therapy optimisation or personalisation. For all stakeholders to be confident in <span class="hlt">model</span>-based clinical decisions, cardiac electrophysiological (CEP) <span class="hlt">models</span> must be demonstrated to be trustworthy and reliable. Credibility, that is, the belief in the predictive capability, of a computational <span class="hlt">model</span> is primarily established by performing <span class="hlt">validation</span>, in which <span class="hlt">model</span> predictions are compared to experimental or clinical data. However, there are numerous challenges to performing <span class="hlt">validation</span> for highly complex multi-scale physiological <span class="hlt">models</span> such as CEP <span class="hlt">models</span>. As a result, credibility of CEP <span class="hlt">model</span> predictions is usually founded upon a wide range of distinct factors, including various types of <span class="hlt">validation</span> results, underlying theory, evidence supporting <span class="hlt">model</span> assumptions, evidence from <span class="hlt">model</span> calibration, all at a variety of scales from ion channel to cell to organ. Consequently, it is often unclear, or a matter for debate, the extent to which a CEP <span class="hlt">model</span> can be trusted for a given application. The aim of this article is to clarify potential rationale for the trustworthiness of CEP <span class="hlt">models</span> by reviewing evidence that has been (or could be) presented to support their credibility. We specifically address the complexity and multi-scale nature of CEP <span class="hlt">models</span> which makes traditional <span class="hlt">model</span> evaluation difficult. In addition, we make explicit some of the credibility justification that we believe is implicitly embedded in the CEP <span class="hlt">modeling</span> literature. Overall, we provide a fresh perspective to CEP <span class="hlt">model</span> credibility, and build a depiction and categorisation of the wide-ranging body of credibility evidence for CEP <span class="hlt">models</span>. This paper also represents a step</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22786574','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22786574"><span>Photoinduced hydrogen evolution in supramolecular devices with a rhenium photosensitizer linked to <span class="hlt">FeFe</span>-hydrogenase <span class="hlt">model</span> complexes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Jianhui; Jiang, Weina</p> <p>2012-08-28</p> <p>Coordination of the pyridyl-attached diiron azadithiolate hexacarbonyl complexes (2 and 3) through the pyridyl nitrogen to the Re on 10-phenanthroline rhenium (5a) and 2,9-diphenyl-1,10-phenanthroline rhenium (5b) forms novel [Re-<span class="hlt">Fe</span>] complexes 7a, 7b and 8 respectively. Under visible light illumination using triethylamine as a sacrificial electron donor and [Re-<span class="hlt">Fe</span>] type complexes (7a, 7b or 8) as catalysts, remarkably increased efficiency was observed for photoinduced hydrogen production with a turnover number reaching 11.8 from complex 7a and 8.75 from 7b. To the best of our knowledge, these are the best values compared to other [Re-<span class="hlt">Fe</span>] photocatalysts reported so far. In contrast to the parent molecules, the turnover number by the intermolecular combination of complexes 6a and 2 showed a value of 5.23, and that from 6b and 2 is 3.8, while no H(2) was detected from 8a and 3 under the same experimental conditions. Obviously, the intramolecular combination of rhenium(I) and [2<span class="hlt">Fe</span>2S] as a catalyst is promising for efficient H(2) evolution, and it is better than the intermolecular multi-component system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMDI33A1623T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMDI33A1623T"><span>Thermoelastic properties of γ-<span class="hlt">Fe</span> and γ- <span class="hlt">Fe</span>64Ni36 alloys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsujino, N.; Nishihara, Y.; Nakajima, Y.; Takahashi, E.; Funakoshi, K.</p> <p>2009-12-01</p> <p>The Earth’s core consists mainly of <span class="hlt">Fe</span>-Ni alloy. Therefore the physical property of <span class="hlt">Fe</span>-Ni alloy is a key issue to understand the planetary core. At 1 bar, γ-<span class="hlt">Fe</span> is known as Anti-Invar alloy which shows anomalously high thermal expansivity, while γ-<span class="hlt">Fe</span>64Ni36 is as a typical Inver-alloy. In addition, previous studies on γ-<span class="hlt">Fe</span>-Ni Invar-alloys reported an anomalous pressure dependence of compression behavior (e.g., Dubrovinsky et al., 2001, Nataf et al., 2006, Matsushita et al., 2008). However, these studies were conducted at limited pressure range (> 6 GPa) or low temperature (30-300 K) conditions to identify physical properties of those alloys in the planetary interior. Therefore, we performed pressure-volume-temperature (P-V-T) measurements on γ-<span class="hlt">Fe</span> and γ-<span class="hlt">Fe</span>-Ni alloys at a wide P-T range of 0-23 GPa and 773-1873 K using the SPEED- Mk.II kawai-type multi-anvil apparatus at the SPring-8 synchrotron facility. On the basis of 2-γ state <span class="hlt">model</span> by Weiss (1963), the thermal expansivity of γ-<span class="hlt">Fe</span> can be decreased significantly with pressure. Our data, however, show no anomalous variation in the thermal expansion coefficient relative to pressure up to 23 GPa. In addition, anomalous pressure dependence on volume of γ-<span class="hlt">Fe</span>64Ni36 reported by Matsushita et al. (2008) was not observed. Fitting 3rd order Birch-Murnaghan EOS and Mie-Grüneisen-Debye EOS to the P-V-T data of γ-<span class="hlt">Fe</span> yielded V 0 = 49.028 ± 0.027 Å 3 , K T 0 = 111.2 ± 1.8 GPa, K ’ T = 5.2 ± 0.2, γ 0 = 2.30 ± 0.04 and q = -0.09 ± 0.21 with the fixed value of θ 0 = 340 K. The P-V data of γ- <span class="hlt">Fe</span>64Ni36 was fittied using the 3rd order Birch-Marnagan, which yields V 0 = 48.85 ± 0.06 Å 3 , K T 0 = 88.1 ± 3.4 GPa, and K ’ 0 = 8.6± 0.5 at 1273 K.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23576093','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23576093"><span>Reaction mechanism of WGS and PROX reactions catalyzed by Pt/oxide catalysts revealed by an <span class="hlt">Fe</span>O(111)/Pt(111) inverse <span class="hlt">model</span> catalyst.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Lingshun; Wu, Zongfang; Jin, Yuekang; Ma, Yunsheng; Huang, Weixin</p> <p>2013-08-07</p> <p>We have employed XPS and TDS to study the adsorption and surface reactions of H2O, CO and HCOOH on an <span class="hlt">Fe</span>O(111)/Pt(111) inverse <span class="hlt">model</span> catalyst. The <span class="hlt">Fe</span>O(111)-Pt(111) interface of the <span class="hlt">Fe</span>O(111)/Pt(111) inverse <span class="hlt">model</span> catalyst exposes coordination-unsaturated <span class="hlt">Fe</span>(II) cations (<span class="hlt">Fe</span>(II)CUS) and the <span class="hlt">Fe</span>(II)CUS cations are capable of modifying the reactivity of neighbouring Pt sites. Water facilely dissociates on the <span class="hlt">Fe</span>(II)CUS cations at the <span class="hlt">Fe</span>O(111)-Pt(111) interface to form hydroxyls that react to form both water and H2 upon heating. Hydroxyls on the <span class="hlt">Fe</span>(II)CUS cations can react with CO(a) on the neighbouring Pt(111) sites to produce CO2 at low temperatures. Hydroxyls act as the co-catalyst in the CO oxidation by hydroxyls to CO2 (PROX reaction), while they act as one of the reactants in the CO oxidation by hydroxyls to CO2 and H2 (WGS reaction), and the recombinative reaction of hydroxyls to produce H2 is the rate-limiting step in the WGS reaction. A comparison of reaction behaviors between the interfacial CO(a) + OH reaction and the formate decomposition reaction suggest that formate is the likely surface intermediate of the CO(a) + OH reaction. These results provide some solid experimental evidence for the associative reaction mechanism of WGS and PROX reactions catalyzed by Pt/oxide catalysts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24076304','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24076304"><span>Testing the <span class="hlt">validity</span> of the International Atomic Energy Agency (IAEA) safety culture <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>López de Castro, Borja; Gracia, Francisco J; Peiró, José M; Pietrantoni, Luca; Hernández, Ana</p> <p>2013-11-01</p> <p>This paper takes the first steps to empirically <span class="hlt">validate</span> the widely used <span class="hlt">model</span> of safety culture of the International Atomic Energy Agency (IAEA), composed of five dimensions, further specified by 37 attributes. To do so, three independent and complementary studies are presented. First, 290 students serve to collect evidence about the face <span class="hlt">validity</span> of the <span class="hlt">model</span>. Second, 48 experts in organizational behavior judge its content <span class="hlt">validity</span>. And third, 468 workers in a Spanish nuclear power plant help to reveal how closely the theoretical five-dimensional <span class="hlt">model</span> can be replicated. Our findings suggest that several attributes of the <span class="hlt">model</span> may not be related to their corresponding dimensions. According to our results, a one-dimensional structure fits the data better than the five dimensions proposed by the IAEA. Moreover, the IAEA <span class="hlt">model</span>, as it stands, seems to have rather moderate content <span class="hlt">validity</span> and low face <span class="hlt">validity</span>. Practical implications for researchers and practitioners are included. Copyright © 2013 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19222567','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19222567"><span>Application of thin-plate spline transformations to finite element <span class="hlt">models</span>, or, how to turn a bog turtle into a spotted turtle to analyze both.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stayton, C Tristan</p> <p>2009-05-01</p> <p>Finite element (<span class="hlt">FE</span>) <span class="hlt">models</span> are popular tools that allow biologists to analyze the biomechanical behavior of complex anatomical structures. However, the expense and time required to create <span class="hlt">models</span> from specimens has prevented comparative studies from involving large numbers of species. A new method is presented for transforming existing <span class="hlt">FE</span> <span class="hlt">models</span> using geometric morphometric methods. Homologous landmark coordinates are digitized on the <span class="hlt">FE</span> <span class="hlt">model</span> and on a target specimen into which the <span class="hlt">FE</span> <span class="hlt">model</span> is being transformed. These coordinates are used to create a thin-plate spline function and coefficients, which are then applied to every node in the <span class="hlt">FE</span> <span class="hlt">model</span>. This function smoothly interpolates the location of points between landmarks, transforming the geometry of the original <span class="hlt">model</span> to match the target. This new <span class="hlt">FE</span> <span class="hlt">model</span> is then used as input in <span class="hlt">FE</span> analyses. This procedure is demonstrated with turtle shells: a Glyptemys muhlenbergii <span class="hlt">model</span> is transformed into Clemmys guttata and Actinemys marmorata <span class="hlt">models</span>. <span class="hlt">Models</span> are loaded and the resulting stresses are compared. The <span class="hlt">validity</span> of the <span class="hlt">models</span> is tested by crushing actual turtle shells in a materials testing machine and comparing those results to predictions from <span class="hlt">FE</span> <span class="hlt">models</span>. General guidelines, cautions, and possibilities for this procedure are also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyB..525..119W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyB..525..119W"><span>First-principles calculations of the structural, elastic and thermodynamic properties of mackinawite (<span class="hlt">Fe</span>S) and pyrite (<span class="hlt">Fe</span>S2)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wen, Xiangli; Liang, Yuxuan; Bai, Pengpeng; Luo, Bingwei; Fang, Teng; Yue, Luo; An, Teng; Song, Weiyu; Zheng, Shuqi</p> <p>2017-11-01</p> <p>The thermodynamic properties of <span class="hlt">Fe</span>-S compounds with different crystal structure are very different. In this study, the structural, elastic and thermodynamic properties of mackinawite (<span class="hlt">Fe</span>S) and pyrite (<span class="hlt">Fe</span>S2) were investigated by first-principles calculations. Examination of the electronic density of states shows that mackinawite (<span class="hlt">Fe</span>S) is metallic and that pyrite (<span class="hlt">Fe</span>S2) is a semiconductor with a band gap of Eg = 1.02 eV. Using the stress-strain method, the elastic properties including the bulk modulus and shear modulus were derived from the elastic Cij data. Density functional perturbation theory (DFPT) calculations within the quasi-harmonic approximation (QHA) were used to calculate the thermodynamic properties, and the two <span class="hlt">Fe</span>-S compounds are found to be dynamically stable. The isothermal bulk modulus, thermal expansion coefficient, heat capacities, Gibbs free energy and entropy of the <span class="hlt">Fe</span>-S compounds are obtained by first-principles phonon calculations. Furthermore, the temperature of the mackinawite (<span class="hlt">Fe</span>S) ⟶ pyrite (<span class="hlt">Fe</span>S2) phase transition at 0 GPa was predicted. Based on the calculation results, the <span class="hlt">model</span> for prediction of <span class="hlt">Fe</span>-S compounds in the <span class="hlt">Fe</span>-H2S-H2O system was improved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhDT........40F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhDT........40F"><span>Structure and magnetism in Co/X, <span class="hlt">Fe</span>/Si, and <span class="hlt">Fe/(Fe</span>Si) multilayers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Franklin, Michael Ray</p> <p></p> <p>Previous studies have shown that magnetic behavior in multilayers formed by repeating a bilayer unit comprised of a ferromagnetic layer and a non-magnetic spacer layer can be affected by small structural differences. For example, a macroscopic property such as giant magnetoresistance (GMR) is believed to depend significantly upon interfacial roughness. In this study, several complimentary structural probes were used to carefully characterize the structure of several sputtered multilayer systems-Co/Ag, Co/Cu, Co/Mo, <span class="hlt">Fe</span>/Si, and <span class="hlt">Fe//[Fe</span>Si/]. X-ray diffraction (XRD) studies were used to examine the long-range structural order of the multilayers perpendicular to the plane of the layers. Transmission electron diffraction (TED) studies were used to probe the long-range order parallel to the layer plane. X-ray Absorption Fine Structure (XAFS) studies were used to determine the average local structural environment of the ferromagnetic atoms. For the Co/X systems, a simple correlation between crystal structure and saturation magnetization is discovered for the Co/Mo system. For the <span class="hlt">Fe</span>/X systems, direct evidence of an <span class="hlt">Fe</span>-silicide is found for the /[<span class="hlt">Fe</span>Si/] spacer layer but not for the Si spacer layer. Additionally, differences were observed in the magnetic behavior between the <span class="hlt">Fe</span> in the nominally pure <span class="hlt">Fe</span> layer and the <span class="hlt">Fe</span> contained in the /[<span class="hlt">Fe</span>Si/] spacer layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25071238','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25071238"><span>Using the split Hopkinson pressure bar to <span class="hlt">validate</span> material <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Church, Philip; Cornish, Rory; Cullis, Ian; Gould, Peter; Lewtas, Ian</p> <p>2014-08-28</p> <p>This paper gives a discussion of the use of the split-Hopkinson bar with particular reference to the requirements of materials <span class="hlt">modelling</span> at QinetiQ. This is to deploy <span class="hlt">validated</span> material <span class="hlt">models</span> for numerical simulations that are physically based and have as little characterization overhead as possible. In order to have confidence that the <span class="hlt">models</span> have a wide range of applicability, this means, at most, characterizing the <span class="hlt">models</span> at low rate and then <span class="hlt">validating</span> them at high rate. The split Hopkinson pressure bar (SHPB) is ideal for this purpose. It is also a very useful tool for analysing material behaviour under non-shock wave loading. This means understanding the output of the test and developing techniques for reliable comparison of simulations with SHPB data. For materials other than metals comparison with an output stress v strain curve is not sufficient as the assumptions built into the classical analysis are generally violated. The method described in this paper compares the simulations with as much <span class="hlt">validation</span> data as can be derived from deployed instrumentation including the raw strain gauge data on the input and output bars, which avoids any assumptions about stress equilibrium. One has to take into account Pochhammer-Chree oscillations and their effect on the specimen and recognize that this is itself also a valuable <span class="hlt">validation</span> test of the material <span class="hlt">model</span>. © 2014 The Author(s) Published by the Royal Society. All rights reserved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25200556','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25200556"><span>Construct <span class="hlt">validity</span> of the ovine <span class="hlt">model</span> in endoscopic sinus surgery training.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Awad, Zaid; Taghi, Ali; Sethukumar, Priya; Tolley, Neil S</p> <p>2015-03-01</p> <p>To demonstrate construct <span class="hlt">validity</span> of the ovine <span class="hlt">model</span> as a tool for training in endoscopic sinus surgery (ESS). Prospective, cross-sectional evaluation study. Over 18 consecutive months, trainees and experts were evaluated in their ability to perform a range of tasks (based on previous face <span class="hlt">validation</span> and descriptive studies conducted by the same group) relating to ESS on the sheep-head <span class="hlt">model</span>. Anonymized randomized video recordings of the above were assessed by two independent and blinded assessors. A <span class="hlt">validated</span> assessment tool utilizing a five-point Likert scale was employed. Construct <span class="hlt">validity</span> was calculated by comparing scores across training levels and experts using mean and interquartile range of global and task-specific scores. Subgroup analysis of the intermediate group ascertained previous experience. Nonparametric descriptive statistics were used, and analysis was carried out using SPSS version 21 (IBM, Armonk, NY). Reliability of the assessment tool was confirmed. The <span class="hlt">model</span> discriminated well between different levels of expertise in global and task-specific scores. A positive correlation was noted between year in training and both global and task-specific scores (P < .001). Experience of the intermediate group was variable, and the number of ESS procedures performed under supervision had the highest impact on performance. This study describes an alternative <span class="hlt">model</span> for ESS training and assessment. It is also the first to demonstrate construct <span class="hlt">validity</span> of the sheep-head <span class="hlt">model</span> for ESS training. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SpWea..14..469G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SpWea..14..469G"><span>Community-wide <span class="hlt">validation</span> of geospace <span class="hlt">model</span> local K-index predictions to support <span class="hlt">model</span> transition to operations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Glocer, A.; Rastätter, L.; Kuznetsova, M.; Pulkkinen, A.; Singer, H. J.; Balch, C.; Weimer, D.; Welling, D.; Wiltberger, M.; Raeder, J.; Weigel, R. S.; McCollough, J.; Wing, S.</p> <p>2016-07-01</p> <p>We present the latest result of a community-wide space weather <span class="hlt">model</span> <span class="hlt">validation</span> effort coordinated among the Community Coordinated <span class="hlt">Modeling</span> Center (CCMC), NOAA Space Weather Prediction Center (SWPC), <span class="hlt">model</span> developers, and the broader science community. <span class="hlt">Validation</span> of geospace <span class="hlt">models</span> is a critical activity for both building confidence in the science results produced by the <span class="hlt">models</span> and in assessing the suitability of the <span class="hlt">models</span> for transition to operations. Indeed, a primary motivation of this work is supporting NOAA/SWPC's effort to select a <span class="hlt">model</span> or <span class="hlt">models</span> to be transitioned into operations. Our <span class="hlt">validation</span> efforts focus on the ability of the <span class="hlt">models</span> to reproduce a regional index of geomagnetic disturbance, the local K-index. Our analysis includes six events representing a range of geomagnetic activity conditions and six geomagnetic observatories representing midlatitude and high-latitude locations. Contingency tables, skill scores, and distribution metrics are used for the quantitative analysis of <span class="hlt">model</span> performance. We consider <span class="hlt">model</span> performance on an event-by-event basis, aggregated over events, at specific station locations, and separated into high-latitude and midlatitude domains. A summary of results is presented in this report, and an online tool for detailed analysis is available at the CCMC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170003055&hterms=motivation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dmotivation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170003055&hterms=motivation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dmotivation"><span>Community-Wide <span class="hlt">Validation</span> of Geospace <span class="hlt">Model</span> Local K-Index Predictions to Support <span class="hlt">Model</span> Transition to Operations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Glocer, A.; Rastaetter, L.; Kuznetsova, M.; Pulkkinen, A.; Singer, H. J.; Balch, C.; Weimer, D.; Welling, D.; Wiltberger, M.; Raeder, J.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20170003055'); toggleEditAbsImage('author_20170003055_show'); toggleEditAbsImage('author_20170003055_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20170003055_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20170003055_hide"></p> <p>2016-01-01</p> <p>We present the latest result of a community-wide space weather <span class="hlt">model</span> <span class="hlt">validation</span> effort coordinated among the Community Coordinated <span class="hlt">Modeling</span> Center (CCMC), NOAA Space Weather Prediction Center (SWPC), <span class="hlt">model</span> developers, and the broader science community. <span class="hlt">Validation</span> of geospace <span class="hlt">models</span> is a critical activity for both building confidence in the science results produced by the <span class="hlt">models</span> and in assessing the suitability of the <span class="hlt">models</span> for transition to operations. Indeed, a primary motivation of this work is supporting NOAA/SWPCs effort to select a <span class="hlt">model</span> or <span class="hlt">models</span> to be transitioned into operations. Our <span class="hlt">validation</span> efforts focus on the ability of the <span class="hlt">models</span> to reproduce a regional index of geomagnetic disturbance, the local K-index. Our analysis includes six events representing a range of geomagnetic activity conditions and six geomagnetic observatories representing midlatitude and high-latitude locations. Contingency tables, skill scores, and distribution metrics are used for the quantitative analysis of <span class="hlt">model</span> performance. We consider <span class="hlt">model</span> performance on an event-by-event basis, aggregated over events, at specific station locations, and separated into high-latitude and midlatitude domains. A summary of results is presented in this report, and an online tool for detailed analysis is available at the CCMC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED470208.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED470208.pdf"><span>Making <span class="hlt">Validated</span> Educational <span class="hlt">Models</span> Central in Preschool Standards.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Schweinhart, Lawrence J.</p> <p></p> <p>This paper presents some ideas to preschool educators and policy makers about how to make <span class="hlt">validated</span> educational <span class="hlt">models</span> central in standards for preschool education and care programs that are available to all 3- and 4-year-olds. Defining an educational <span class="hlt">model</span> as a coherent body of program practices, curriculum content, program and child, and teacher…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSH53A2160M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSH53A2160M"><span>Web Based Semi-automatic Scientific <span class="hlt">Validation</span> of <span class="hlt">Models</span> of the Corona and Inner Heliosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>MacNeice, P. J.; Chulaki, A.; Taktakishvili, A.; Kuznetsova, M. M.</p> <p>2013-12-01</p> <p><span class="hlt">Validation</span> is a critical step in preparing <span class="hlt">models</span> of the corona and inner heliosphere for future roles supporting either or both the scientific research community and the operational space weather forecasting community. <span class="hlt">Validation</span> of forecasting quality tends to focus on a short list of key features in the <span class="hlt">model</span> solutions, with an unchanging order of priority. Scientific <span class="hlt">validation</span> exposes a much larger range of physical processes and features, and as the <span class="hlt">models</span> evolve to better represent features of interest, the research community tends to shift its focus to other areas which are less well understood and <span class="hlt">modeled</span>. Given the more comprehensive and dynamic nature of scientific <span class="hlt">validation</span>, and the limited resources available to the community to pursue this, it is imperative that the community establish a semi-automated process which engages the <span class="hlt">model</span> developers directly into an ongoing and evolving <span class="hlt">validation</span> process. In this presentation we describe the ongoing design and develpment of a web based facility to enable this type of <span class="hlt">validation</span> of <span class="hlt">models</span> of the corona and inner heliosphere, on the growing list of <span class="hlt">model</span> results being generated, and on strategies we have been developing to account for <span class="hlt">model</span> results that incorporate adaptively refined numerical grids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MAR.T1230A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MAR.T1230A"><span>Tunnel Magneto Resistance of <span class="hlt">Fe/Insulator/Fe</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aryee, Dennis; Seifu, Dereje</p> <p></p> <p>Tri-layer thin films of <span class="hlt">Fe/Insulator/Fe</span> were synthesized using magnetron DC/ RF sputtering with MgO insulator and Bi2Te3 topological insulators as middle buffer layer. The multi-layered samples thus produced were studied using in-house built magneto-optic Kerr effect (MOKE) instrument, vibrating sample magnetometer (VSM), torque magnetometer (TMM), AFM, MFM, and magneto-resistance (MR). This system, that is <span class="hlt">Fe/Insulator/Fe</span> on MgO(100) substrate, is a well-known tunnel magneto resistance (TMR) structure often used in magnetic tunnel junction (MTJ) devices. TMR effect is a method by which MTJs are used in developing magneto-resistive random access memory (MRAM), magnetic sensors, and novel logic devices. The main purpose behind this research is to measure the magnetic anisotropy of <span class="hlt">Fe</span>/Insulator /<span class="hlt">Fe</span> structure and correlate it to magneto-resistance. In this presentation, we will present results from MOKE, VSM, TMM, AFM, MFM, and MR studies of <span class="hlt">Fe/Insulator/Fe</span> on MgO(100). We would like to acknowledge support by NSF-MRI-DMR-1337339.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.468.4311L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.468.4311L"><span>Non-LTE line formation of <span class="hlt">Fe</span> in late-type stars - IV. <span class="hlt">Modelling</span> of the solar centre-to-limb variation in 3D</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lind, K.; Amarsi, A. M.; Asplund, M.; Barklem, P. S.; Bautista, M.; Bergemann, M.; Collet, R.; Kiselman, D.; Leenaarts, J.; Pereira, T. M. D.</p> <p>2017-07-01</p> <p>Our ability to <span class="hlt">model</span> the shapes and strengths of iron lines in the solar spectrum is a critical test of the accuracy of the solar iron abundance, which sets the absolute zero-point of all stellar metallicities. We use an extensive 463-level <span class="hlt">Fe</span> atom with new photoionization cross-sections for <span class="hlt">Fe</span> I and quantum mechanical calculations of collisional excitation and charge transfer with neutral hydrogen; the latter effectively remove a free parameter that has hampered all previous line formation studies of <span class="hlt">Fe</span> in non-local thermodynamic equilibrium (NLTE). For the first time, we use realistic 3D NLTE calculations of <span class="hlt">Fe</span> for a quantitative comparison to solar observations. We confront our theoretical line profiles with observations taken at different viewing angles across the solar disc with the Swedish 1-m Solar Telescope. We find that 3D <span class="hlt">modelling</span> well reproduces the observed centre-to-limb behaviour of spectral lines overall, but highlight aspects that may require further work, especially cross-sections for inelastic collisions with electrons. Our inferred solar iron abundance is log (ɛ<span class="hlt">Fe</span>) = 7.48 ± 0.04 dex.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1434659-modeling-adsorbate-coverage-distribution-over-multi-faceted-catalytic-grain-presence-electric-field-fe-from-first-principles','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1434659-modeling-adsorbate-coverage-distribution-over-multi-faceted-catalytic-grain-presence-electric-field-fe-from-first-principles"><span><span class="hlt">Modeling</span> the Adsorbate Coverage Distribution Over a Multi-Faceted Catalytic Grain in the Presence of an Electric Field: O/<span class="hlt">Fe</span> from First Principles</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bray, Jacob; Hensley, Alyssa J. R.; Collinge, Greg</p> <p></p> <p>The impact of an external electric field on the concerted behavior of oxygen over a multi-faceted catalytic <span class="hlt">Fe</span> grain is determined via the interpolation of ab initio <span class="hlt">models</span> of oxygen adsorption on <span class="hlt">Fe</span>(100), <span class="hlt">Fe</span>(110), and <span class="hlt">Fe</span>(111) in the presence of an external electric field. The application of both negative and positive electric fields weaken the adsorption strength for oxygen on all three surface facets, with <span class="hlt">Fe</span>(110) experiencing the greatest effect. Kinetic <span class="hlt">models</span> of a multi-faceted catalytic <span class="hlt">Fe</span> grain show that the average oxygen coverage over the grain surface is reduced under the influence of both a negative and positive electricmore » field, which are consistent with phase diagram results at comparable pressures. Furthermore, we show that there is a weak synergistic effect between a Pd promoter and a positive electric field on the oxygen adsorption energy, i.e. the Pd promoter and electric field combination weaken the oxygen adsorption energy to a greater degree than the simple addition of both components separately. In conclusion, the work shows that the application of an applied external electric field may be a useful tool in fine-tuning chemical properties of <span class="hlt">Fe</span>-based catalysts in hydrodeoxygenation applications.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1434659-modeling-adsorbate-coverage-distribution-over-multi-faceted-catalytic-grain-presence-electric-field-fe-from-first-principles','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1434659-modeling-adsorbate-coverage-distribution-over-multi-faceted-catalytic-grain-presence-electric-field-fe-from-first-principles"><span><span class="hlt">Modeling</span> the Adsorbate Coverage Distribution Over a Multi-Faceted Catalytic Grain in the Presence of an Electric Field: O/<span class="hlt">Fe</span> from First Principles</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Bray, Jacob; Hensley, Alyssa J. R.; Collinge, Greg; ...</p> <p>2018-04-15</p> <p>The impact of an external electric field on the concerted behavior of oxygen over a multi-faceted catalytic <span class="hlt">Fe</span> grain is determined via the interpolation of ab initio <span class="hlt">models</span> of oxygen adsorption on <span class="hlt">Fe</span>(100), <span class="hlt">Fe</span>(110), and <span class="hlt">Fe</span>(111) in the presence of an external electric field. The application of both negative and positive electric fields weaken the adsorption strength for oxygen on all three surface facets, with <span class="hlt">Fe</span>(110) experiencing the greatest effect. Kinetic <span class="hlt">models</span> of a multi-faceted catalytic <span class="hlt">Fe</span> grain show that the average oxygen coverage over the grain surface is reduced under the influence of both a negative and positive electricmore » field, which are consistent with phase diagram results at comparable pressures. Furthermore, we show that there is a weak synergistic effect between a Pd promoter and a positive electric field on the oxygen adsorption energy, i.e. the Pd promoter and electric field combination weaken the oxygen adsorption energy to a greater degree than the simple addition of both components separately. In conclusion, the work shows that the application of an applied external electric field may be a useful tool in fine-tuning chemical properties of <span class="hlt">Fe</span>-based catalysts in hydrodeoxygenation applications.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2840173','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2840173"><span>A <span class="hlt">model</span> for the CO-inhibited form of [Ni<span class="hlt">Fe</span>] hydrogenase: synthesis of (CO)3<span class="hlt">Fe</span>(μ-StBu)3Ni{SC6H3-2,6-(mesityl)2} and reversible CO addition at the Ni site</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ohki, Yasuhiro; Yasumura, Kazunari; Ando, Masaru; Shimokata, Satoko; Tatsumi, Kazuyuki</p> <p>2010-01-01</p> <p>A [Ni<span class="hlt">Fe</span>] hydrogenase <span class="hlt">model</span> compound having a distorted trigonal-pyramidal nickel center, (CO)3<span class="hlt">Fe</span>(μ-StBu)3Ni(SDmp), 1 (Dmp = C6H3-2,6-(mesityl)2), was synthesized from the reaction of the tetranuclear <span class="hlt">Fe-Ni-Ni-Fe</span> complex [(CO)3<span class="hlt">Fe</span>(μ-StBu)3Ni]2(μ-Br)2, 2 with NaSDmp at -40 °C. The nickel site of complex 1 was found to add CO or CNtBu at -40 °C to give (CO)3<span class="hlt">Fe</span>(StBu)(μ-StBu)2Ni(CO)(SDmp), 3, or (CO)3<span class="hlt">Fe</span>(StBu)(μ-StBu)2Ni(CNtBu)(SDmp), 4, respectively. One of the CO bands of 3, appearing at 2055 cm-1 in the infrared spectrum, was assigned as the Ni-CO band, and this frequency is comparable to those observed for the CO-inhibited forms of [Ni<span class="hlt">Fe</span>] hydrogenase. Like the CO-inhibited forms of [Ni<span class="hlt">Fe</span>] hydrogenase, the coordination of CO at the nickel site of 1 is reversible, while the CNtBu adduct 4 is more robust. PMID:20147622</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3670880','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3670880"><span>Predictive <span class="hlt">Validation</span> of an Influenza Spread <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hyder, Ayaz; Buckeridge, David L.; Leung, Brian</p> <p>2013-01-01</p> <p>Background <span class="hlt">Modeling</span> plays a critical role in mitigating impacts of seasonal influenza epidemics. Complex simulation <span class="hlt">models</span> are currently at the forefront of evaluating optimal mitigation strategies at multiple scales and levels of organization. Given their evaluative role, these <span class="hlt">models</span> remain limited in their ability to predict and forecast future epidemics leading some researchers and public-health practitioners to question their usefulness. The objective of this study is to evaluate the predictive ability of an existing complex simulation <span class="hlt">model</span> of influenza spread. Methods and Findings We used extensive data on past epidemics to demonstrate the process of predictive <span class="hlt">validation</span>. This involved generalizing an individual-based <span class="hlt">model</span> for influenza spread and fitting it to laboratory-confirmed influenza infection data from a single observed epidemic (1998–1999). Next, we used the fitted <span class="hlt">model</span> and modified two of its parameters based on data on real-world perturbations (vaccination coverage by age group and strain type). Simulating epidemics under these changes allowed us to estimate the deviation/error between the expected epidemic curve under perturbation and observed epidemics taking place from 1999 to 2006. Our <span class="hlt">model</span> was able to forecast absolute intensity and epidemic peak week several weeks earlier with reasonable reliability and depended on the method of forecasting-static or dynamic. Conclusions Good predictive ability of influenza epidemics is critical for implementing mitigation strategies in an effective and timely manner. Through the process of predictive <span class="hlt">validation</span> applied to a current complex simulation <span class="hlt">model</span> of influenza spread, we provided users of the <span class="hlt">model</span> (e.g. public-health officials and policy-makers) with quantitative metrics and practical recommendations on mitigating impacts of seasonal influenza epidemics. This methodology may be applied to other <span class="hlt">models</span> of communicable infectious diseases to test and potentially improve their predictive</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1375458','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1375458"><span>3D-<span class="hlt">FE</span> <span class="hlt">Modeling</span> of 316 SS under Strain-Controlled Fatigue Loading and CFD Simulation of PWR Surge Line</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Mohanty, Subhasish; Barua, Bipul; Listwan, Joseph</p> <p></p> <p>In financial year 2017, we are focusing on developing a mechanistic fatigue <span class="hlt">model</span> of surge line pipes for pressurized water reactors (PWRs). To that end, we plan to perform the following tasks: (1) conduct stress- and strain-controlled fatigue testing of surge-line base metal such as 316 stainless steel (SS) under constant, variable, and random fatigue loading, (2) develop cyclic plasticity material <span class="hlt">models</span> of 316 SS, (3) develop one-dimensional (1D) analytical or closed-form <span class="hlt">model</span> to <span class="hlt">validate</span> the material <span class="hlt">models</span> and to understand the mechanics associated with 316 SS cyclic hardening and/or softening, (4) develop three-dimensional (3D) finite element (<span class="hlt">FE</span>) <span class="hlt">models</span> withmore » implementation of evolutionary cyclic plasticity, and (5) develop computational fluid dynamics (CFD) <span class="hlt">model</span> for thermal stratification, thermal-mechanical stress, and fatigue of example reactor components, such as a PWR surge line under plant heat-up, cool-down, and normal operation with/without grid-load-following. This semi-annual progress report presents the work completed on the above tasks for a 316 SS laboratory-scale specimen subjected to strain-controlled cyclic loading with constant, variable, and random amplitude. This is the first time that the accurate 3D-<span class="hlt">FE</span> <span class="hlt">modeling</span> of the specimen for its entire fatigue life, including the hardening and softening behavior, has been achieved. We anticipate that this work will pave the way for the development of a fully mechanistic-computer <span class="hlt">model</span> that can be used for fatigue evaluation of safety-critical metallic components, which are traditionally evaluated by heavy reliance on time-consuming and costly test-based approaches. This basic research will not only help the nuclear reactor industry for fatigue evaluation of reactor components in a cost effective and less time-consuming way, but will also help other safety-related industries, such as aerospace, which is heavily dependent on test-based approaches, where a single full-scale fatigue test can</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSA42A..05C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSA42A..05C"><span>Thermosphere-Ionosphere <span class="hlt">Fe/Fe</span>+ (TIFe) Layers and Their Coupling with Geomagnetic Storms and Solar Wind</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chu, X.; Xu, Z.; Zhao, J.; Yu, Z.; Knipp, D. J.; Kilcommons, L. M.; Chen, C.; Fong, W.; Barry, I. F.; Hartinger, M.</p> <p>2016-12-01</p> <p>The discovery of thermospheric neutral <span class="hlt">Fe</span> layers by lidar observations in Antarctica has opened a new door to explore the space-atmosphere interactions with ground-based instruments, especially in the least understood but crucially important altitude range of 100-200 km. These neutral metal layers provide excellent tracers for modern resonance lidars to measure the neutral wind and temperature directly, complementing the radar measurements of the ionosphere and the magnetometer measurements of the geomagnetic field. Even more exciting, the neutral metal layers in the thermosphere provide a natural laboratory to test our fundamental understandings of the atmosphere-ionosphere-magnetosphere (AIM) coupling and processes. The stunning <span class="hlt">Fe</span> layer event on 28 May 2011 with clear gravity wave signatures has been simulated successfully with the University of Colorado Thermosphere-Ionosphere <span class="hlt">Fe/Fe</span>+ (TIFe) <span class="hlt">model</span>, confirming the theoretical hypothesis that such thermospheric <span class="hlt">Fe</span> layers are produced through the neutralization of converged <span class="hlt">Fe</span>+layers. Over 5.5 years of lidar observations at McMurdo have revealed many more cases with variety of patterns - besides the `gravity wave' patterns, there are `diffusive' patterns with both upward and downward phase progressions of <span class="hlt">Fe</span> layers, and `superposition' patterns with both gravity wave signature and diffusive background. Surprisingly, these <span class="hlt">Fe</span> layer events exhibit close correlations with geomagnetic storms. They also correspond to remarkable activity of extreme solar wind events, e.g., high-speed stream (HSS) and coronal mass ejection (CME), etc. This paper conducts a systematic investigation of the coupling among TIFe layers, geomagnetic storms, solar wind and IMF via combining ground-based lidar, magnetometer, and SuperDARN data with DMSP, ACE and WIND satellite data along with the TIFe <span class="hlt">model</span> simulations. We aim to quantitatively determine the relationship between TIFe and magnetic storms, and explore the mechanisms responsible for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JMMM..345...29A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JMMM..345...29A"><span>magnum.<span class="hlt">fe</span>: A micromagnetic finite-element simulation code based on FEniCS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abert, Claas; Exl, Lukas; Bruckner, Florian; Drews, André; Suess, Dieter</p> <p>2013-11-01</p> <p>We have developed a finite-element micromagnetic simulation code based on the FEniCS package called magnum.<span class="hlt">fe</span>. Here we describe the numerical methods that are applied as well as their implementation with FEniCS. We apply a transformation method for the solution of the demagnetization-field problem. A semi-implicit weak formulation is used for the integration of the Landau-Lifshitz-Gilbert equation. Numerical experiments show the <span class="hlt">validity</span> of simulation results. magnum.<span class="hlt">fe</span> is open source and well documented. The broad feature range of the FEniCS package makes magnum.<span class="hlt">fe</span> a good choice for the implementation of novel micromagnetic finite-element algorithms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26709740','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26709740"><span>Enhanced Stability of the <span class="hlt">Fe</span>(II)/Mn(II) State in a Synthetic <span class="hlt">Model</span> of Heterobimetallic Cofactor Assembly.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kerber, William D; Goheen, Joshua T; Perez, Kaitlyn A; Siegler, Maxime A</p> <p>2016-01-19</p> <p>Heterobimetallic Mn/<span class="hlt">Fe</span> cofactors are found in the R2 subunit of class Ic ribonucleotide reductases (R2c) and R2-like ligand binding oxidases (R2lox). Selective cofactor assembly is due at least in part to the thermodynamics of M(II) binding to the apoprotein. We report here equilibrium studies of <span class="hlt">Fe</span>(II)/Mn(II) discrimination in the biomimetic <span class="hlt">model</span> system H5(F-HXTA) (5-fluoro-2-hydroxy-1,3-xylene-α,α'-diamine-N,N,N',N'-tetraacetic acid). The homobimetallic F-HXTA complexes [<span class="hlt">Fe</span>(H2O)6][1]2·14H2O and [Mn(H2O)6][2]2·14H2O (1 = [<span class="hlt">Fe</span>(II)2(F-HXTA)(H2O)4](-); 2 = [Mn(II)2(F-HXTA)(H2O)4](-)) were characterized by single crystal X-ray diffraction. NMR data show that 1 retains its structure in solution (2 is NMR silent). Metal exchange is facile, and the heterobimetallic complex [<span class="hlt">Fe</span>(II)Mn(II)(F-HXTA)(H2O)4](-) (3) is formed from mixtures of 1 and 2. (19)F NMR was used to quantify 1 and 3 in the presence of excess M(II)(aq) at various metal ratios, and equilibrium constants for <span class="hlt">Fe</span>(II)/Mn(II) discrimination were calculated from these data. <span class="hlt">Fe</span>(II) is preferred over Mn(II) with K1 = 182 ± 13 for complete replacement (2 ⇌ 1). This relatively modest preference is attributed to a hard-soft acid-base mismatch between the divalent cations and the polycarboxylate ligand. The stepwise constants for replacement are K2 = 20.1 ± 1.3 (2 ⇌ 3) and K3 = 9.1 ± 1.1 (3 ⇌ 1). K2 > K3 demonstrates enhanced stability of the heterobimetallic state beyond what is expected for simple Mn(II) → <span class="hlt">Fe</span>(II) replacement. The relevance to <span class="hlt">Fe</span>(II)/Mn(II) discrimination in R2c and R2lox proteins is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1338838-image-based-multi-scale-simulation-experimental-validation-thermal-conductivity-lanthanum-zirconate','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1338838-image-based-multi-scale-simulation-experimental-validation-thermal-conductivity-lanthanum-zirconate"><span>Image-based multi-scale simulation and experimental <span class="hlt">validation</span> of thermal conductivity of lanthanum zirconate</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Guo, Xingye; Hu, Bin; Wei, Changdong</p> <p></p> <p>Lanthanum zirconate (La2Zr2O7) is a promising candidate material for thermal barrier coating (TBC) applications due to its low thermal conductivity and high-temperature phase stability. In this work, a novel image-based multi-scale simulation framework combining molecular dynamics (MD) and finite element (<span class="hlt">FE</span>) calculations is proposed to study the thermal conductivity of La2Zr2O7 coatings. Since there is no experimental data of single crystal La2Zr2O7 thermal conductivity, a reverse non-equilibrium molecular dynamics (reverse NEMD) approach is first employed to compute the temperature-dependent thermal conductivity of single crystal La2Zr2O7. The single crystal data is then passed to a <span class="hlt">FE</span> <span class="hlt">model</span> which takes into accountmore » of realistic thermal barrier coating microstructures. The predicted thermal conductivities from the <span class="hlt">FE</span> <span class="hlt">model</span> are in good agreement with experimental <span class="hlt">validations</span> using both flash laser technique and pulsed thermal imaging-multilayer analysis. The framework proposed in this work provides a powerful tool for future design of advanced coating systems. (C) 2016 Elsevier Ltd. All rights reserved.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1949b0012B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1949b0012B"><span>Forward ultrasonic <span class="hlt">model</span> <span class="hlt">validation</span> using wavefield imaging methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blackshire, James L.</p> <p>2018-04-01</p> <p>The <span class="hlt">validation</span> of forward ultrasonic wave propagation <span class="hlt">models</span> in a complex titanium polycrystalline material system is accomplished using wavefield imaging methods. An innovative measurement approach is described that permits the visualization and quantitative evaluation of bulk elastic wave propagation and scattering behaviors in the titanium material for a typical focused immersion ultrasound measurement process. Results are provided for the determination and direct comparison of the ultrasonic beam's focal properties, mode-converted shear wave position and angle, and scattering and reflection from millimeter-sized microtexture regions (MTRs) within the titanium material. The approach and results are important with respect to understanding the root-cause backscatter signal responses generated in aerospace engine materials, where <span class="hlt">model</span>-assisted methods are being used to understand the probabilistic nature of the backscatter signal content. Wavefield imaging methods are shown to be an effective means for corroborating and <span class="hlt">validating</span> important forward <span class="hlt">model</span> predictions in a direct manner using time- and spatially-resolved displacement field amplitude measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26488283','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26488283"><span>How Is <span class="hlt">Fe</span>-S Cluster Formation Regulated?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mettert, Erin L; Kiley, Patricia J</p> <p>2015-01-01</p> <p>Iron-sulfur (<span class="hlt">Fe</span>-S) clusters are fundamental to numerous biological processes in most organisms, but these protein cofactors can be prone to damage by various oxidants (e.g., O2, reactive oxygen species, and reactive nitrogen species) and toxic levels of certain metals (e.g., cobalt and copper). Furthermore, their synthesis can also be directly influenced by the level of available iron in the environment. Consequently, the cellular need for <span class="hlt">Fe</span>-S cluster biogenesis varies with fluctuating growth conditions. To accommodate changes in <span class="hlt">Fe</span>-S demand, microorganisms employ diverse regulatory strategies to tailor <span class="hlt">Fe</span>-S cluster biogenesis according to their surroundings. Here, we review the mechanisms that regulate <span class="hlt">Fe</span>-S cluster formation in bacteria, primarily focusing on control of the Isc and Suf <span class="hlt">Fe</span>-S cluster biogenesis systems in the <span class="hlt">model</span> bacterium Escherichia coli.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSCT11A..04C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSCT11A..04C"><span>Tracing anthropogenic aerosol <span class="hlt">Fe</span> sources in the North Atlantic Ocean using dissolved <span class="hlt">Fe</span> isotope ratios</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Conway, T. M.; Shelley, R.; Aguilar-Islas, A. M.; Landing, W. M.; Mahowald, N. M.; John, S.</p> <p>2016-02-01</p> <p>Supply of iron (<span class="hlt">Fe</span>) to the surface ocean from atmospheric deposition plays a vital role in marine biogeochemical cycles, especially in <span class="hlt">Fe</span>-limited areas or regions close to dust sources. However, large uncertainties remain over the fluxes, solubility and bioavailability of <span class="hlt">Fe</span> supplied by aerosol dust. Additionally, aerosol <span class="hlt">Fe</span> is likely to consist of a mixture of natural and anthropogenic (urban, biomass burning and combustion) components, which may have very different solubilities in seawater [e.g. 1]. To constrain soluble <span class="hlt">Fe</span> supply to the oceans, it is thus vitally important to understand the relative contributions of different types of aerosol <span class="hlt">Fe</span>, their solubilities and spatial distributions. Stable <span class="hlt">Fe</span> isotopes (δ56<span class="hlt">Fe</span>) may offer a way to discriminate between different dust sources [2], because of differential fractionation during a range of chemical processes. In this study, we measured δ56<span class="hlt">Fe</span> in North Atlantic marine aerosols collected during two US GEOTRACES GA03 cruises (Lisbon to Woods Hole via Cape Verde, 2010-11) and we present δ56<span class="hlt">Fe</span> measurements (relative to IRMM-014) from both the bulk aerosol (HF-HNO3 digested) and the water-soluble (10s ultrapure water leach) fractions. Aerosols collected from different air-masses (Saharan, European and N. American) allowed us to investigate the variability in δ56<span class="hlt">Fe</span> due to different regional dust sources. The bulk phase was characterized by near-crustal δ56<span class="hlt">Fe</span> values of +0.1±0.2‰, indicating the dominance of mineral dust. In contrast, the water-soluble fraction showed great variability; aerosols from European and North American air-masses were very isotopically light (-1.2±0.2‰ and -1.1±0.7‰) while those from Saharan air-masses were crustal (+0.1‰). Comparison of this data with isotope-informed <span class="hlt">model</span> predictions of soluble <span class="hlt">Fe</span> from mineral and anthropogenic sources (combustion, biofuels and biomass burning) [1], suggests that the data is consistent with mixing of either 1) <span class="hlt">Fe</span> from mineral dust (+0.1‰) and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H51A1169A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H51A1169A"><span>Three Dimensional Vapor Intrusion <span class="hlt">Modeling</span>: <span class="hlt">Model</span> <span class="hlt">Validation</span> and Uncertainty Analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akbariyeh, S.; Patterson, B.; Rakoczy, A.; Li, Y.</p> <p>2013-12-01</p> <p>Volatile organic chemicals (VOCs), such as chlorinated solvents and petroleum hydrocarbons, are prevalent groundwater contaminants due to their improper disposal and accidental spillage. In addition to contaminating groundwater, VOCs may partition into the overlying vadose zone and enter buildings through gaps and cracks in foundation slabs or basement walls, a process termed vapor intrusion. Vapor intrusion of VOCs has been recognized as a detrimental source for human exposures to potential carcinogenic or toxic compounds. The simulation of vapor intrusion from a subsurface source has been the focus of many studies to better understand the process and guide field investigation. While multiple analytical and numerical <span class="hlt">models</span> were developed to simulate the vapor intrusion process, detailed <span class="hlt">validation</span> of these <span class="hlt">models</span> against well controlled experiments is still lacking, due to the complexity and uncertainties associated with site characterization and soil gas flux and indoor air concentration measurement. In this work, we present an effort to <span class="hlt">validate</span> a three-dimensional vapor intrusion <span class="hlt">model</span> based on a well-controlled experimental quantification of the vapor intrusion pathways into a slab-on-ground building under varying environmental conditions. Finally, a probabilistic approach based on Monte Carlo simulations is implemented to determine the probability distribution of indoor air concentration based on the most uncertain input parameters.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160006380','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160006380"><span>Software <span class="hlt">Validation</span> via <span class="hlt">Model</span> Animation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dutle, Aaron M.; Munoz, Cesar A.; Narkawicz, Anthony J.; Butler, Ricky W.</p> <p>2015-01-01</p> <p>This paper explores a new approach to <span class="hlt">validating</span> software implementations that have been produced from formally-verified algorithms. Although visual inspection gives some confidence that the implementations faithfully reflect the formal <span class="hlt">models</span>, it does not provide complete assurance that the software is correct. The proposed approach, which is based on animation of formal specifications, compares the outputs computed by the software implementations on a given suite of input values to the outputs computed by the formal <span class="hlt">models</span> on the same inputs, and determines if they are equal up to a given tolerance. The approach is illustrated on a prototype air traffic management system that computes simple kinematic trajectories for aircraft. Proofs for the mathematical <span class="hlt">models</span> of the system's algorithms are carried out in the Prototype Verification System (PVS). The animation tool PVSio is used to evaluate the formal <span class="hlt">models</span> on a set of randomly generated test cases. Output values computed by PVSio are compared against output values computed by the actual software. This comparison improves the assurance that the translation from formal <span class="hlt">models</span> to code is faithful and that, for example, floating point errors do not greatly affect correctness and safety properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..188a2014F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..188a2014F"><span>Role of temperature-dependent O-p-<span class="hlt">Fe</span>-d hybridization parameter in the metal-insulator transition of <span class="hlt">Fe</span>3O4: a theoretical study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fauzi, A. D.; Majidi, M. A.; Rusydi, A.</p> <p>2017-04-01</p> <p>We propose a simple tight-binding based <span class="hlt">model</span> for <span class="hlt">Fe</span>3O4 that captures the preference of ferrimagnetic over ferromagnetic spin configuration of the system. Our <span class="hlt">model</span> is consistent with previous theoretical and experimental studies suggesting that the system is half metallic, in which spin polarized electrons hop only among the <span class="hlt">Fe</span> B sites. To address the metal-insulator transition (MIT) we propose that the strong correlation among electrons, which may also be influenced by the electron-phonon interactions, manifest as the temperature-dependence of the O-p-<span class="hlt">Fe</span>-d hybridization parameter, particularly <span class="hlt">Fe</span>-d belonging to one of the <span class="hlt">Fe</span> B sites (denoted as {t}{{<span class="hlt">Fe</span>B}-{{O}}}(2)). By proposing that this parameter increases as the temperature decreases, our density-of-states calculation successfully captures a gap opening at the Fermi level, transforming the system from half metal to insulator. Within this <span class="hlt">model</span> along with the corresponding choice of parameters and a certain profile of the temperature dependence of {t}{{<span class="hlt">Fe</span>B}-{{O}}}(2), we calculate the resistivity of the system as a function of temperature. Our calculation result reveals the drastic uprising trend of the resistivity profile as the temperature decreases, with the MIT transition temperature located around 100 K, which is in agreement with experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150006032','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150006032"><span>Calibration of Predictor <span class="hlt">Models</span> Using Multiple <span class="hlt">Validation</span> Experiments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crespo, Luis G.; Kenny, Sean P.; Giesy, Daniel P.</p> <p>2015-01-01</p> <p>This paper presents a framework for calibrating computational <span class="hlt">models</span> using data from several and possibly dissimilar <span class="hlt">validation</span> experiments. The offset between <span class="hlt">model</span> predictions and observations, which might be caused by measurement noise, <span class="hlt">model</span>-form uncertainty, and numerical error, drives the process by which uncertainty in the <span class="hlt">models</span> parameters is characterized. The resulting description of uncertainty along with the computational <span class="hlt">model</span> constitute a predictor <span class="hlt">model</span>. Two types of predictor <span class="hlt">models</span> are studied: Interval Predictor <span class="hlt">Models</span> (IPMs) and Random Predictor <span class="hlt">Models</span> (RPMs). IPMs use sets to characterize uncertainty, whereas RPMs use random vectors. The propagation of a set through a <span class="hlt">model</span> makes the response an interval valued function of the state, whereas the propagation of a random vector yields a random process. Optimization-based strategies for calculating both types of predictor <span class="hlt">models</span> are proposed. Whereas the formulations used to calculate IPMs target solutions leading to the interval value function of minimal spread containing all observations, those for RPMs seek to maximize the <span class="hlt">models</span>' ability to reproduce the distribution of observations. Regarding RPMs, we choose a structure for the random vector (i.e., the assignment of probability to points in the parameter space) solely dependent on the prediction error. As such, the probabilistic description of uncertainty is not a subjective assignment of belief, nor is it expected to asymptotically converge to a fixed value, but instead it casts the <span class="hlt">model</span>'s ability to reproduce the experimental data. This framework enables evaluating the spread and distribution of the predicted response of target applications depending on the same parameters beyond the <span class="hlt">validation</span> domain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/4757','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/4757"><span><span class="hlt">Validation</span> of the measure automobile emissions <span class="hlt">model</span> : a statistical analysis</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>2000-09-01</p> <p>The Mobile Emissions Assessment System for Urban and Regional Evaluation (MEASURE) <span class="hlt">model</span> provides an external <span class="hlt">validation</span> capability for hot stabilized option; the <span class="hlt">model</span> is one of several new modal emissions <span class="hlt">models</span> designed to predict hot stabilized e...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4233956','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4233956"><span>Quasi-static image-based immersed boundary-finite element <span class="hlt">model</span> of left ventricle under diastolic loading</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gao, Hao; Wang, Huiming; Berry, Colin; Luo, Xiaoyu; Griffith, Boyce E</p> <p>2014-01-01</p> <p>Finite stress and strain analyses of the heart provide insight into the biomechanics of myocardial function and dysfunction. Herein, we describe progress toward dynamic patient-specific <span class="hlt">models</span> of the left ventricle using an immersed boundary (IB) method with a finite element (<span class="hlt">FE</span>) structural mechanics <span class="hlt">model</span>. We use a structure-based hyperelastic strain-energy function to describe the passive mechanics of the ventricular myocardium, a realistic anatomical geometry reconstructed from clinical magnetic resonance images of a healthy human heart, and a rule-based fiber architecture. Numerical predictions of this IB/<span class="hlt">FE</span> <span class="hlt">model</span> are compared with results obtained by a commercial <span class="hlt">FE</span> solver. We demonstrate that the IB/<span class="hlt">FE</span> <span class="hlt">model</span> yields results that are in good agreement with those of the conventional <span class="hlt">FE</span> <span class="hlt">model</span> under diastolic loading conditions, and the predictions of the LV <span class="hlt">model</span> using either numerical method are shown to be consistent with previous computational and experimental data. These results are among the first to analyze the stress and strain predictions of IB <span class="hlt">models</span> of ventricular mechanics, and they serve both to verify the IB/<span class="hlt">FE</span> simulation framework and to <span class="hlt">validate</span> the IB/<span class="hlt">FE</span> <span class="hlt">model</span>. Moreover, this work represents an important step toward using such <span class="hlt">models</span> for fully dynamic fluid–structure interaction simulations of the heart. © 2014 The Authors. International Journal for Numerical Methods in Engineering published by John Wiley & Sons, Ltd. PMID:24799090</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5244426','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5244426"><span>Co<span class="hlt">Fe</span>2O4@MIL-100(<span class="hlt">Fe</span>) hybrid magnetic nanoparticles exhibit fast and selective adsorption of arsenic with high adsorption capacity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yang, Ji-Chun; Yin, Xue-Bo</p> <p>2017-01-01</p> <p>In this study, we report the synthesis and application of mesoporous Co<span class="hlt">Fe</span>2O4@MIL-100(<span class="hlt">Fe</span>) hybrid magnetic nanoparticles (MNPs) for the simultaneous removal of inorganic arsenic (iAs). The hybrid adsorbent had a core-shell and mesoporous structure with an average diameter of 260 nm. The nanoscale size and mesoporous character impart a fast adsorption rate and high adsorption capacity for iAs. In total, 0.1 mg L−1 As(V) and As(III) could be adsorbed within 2 min, and the maximum adsorption capacities were 114.8 mg g−1 for As(V) and 143.6 mg g−1 for As(III), higher than most previously reported adsorbents. The anti-interference capacity for iAs adsorption was improved by the electrostatic repulsion and size exclusion effects of the MIL-100(<span class="hlt">Fe</span>) shell, which also decreased the zero-charge point of the hybrid absorbent for a broad pH adsorption range. The adsorption mechanisms of iAs on the MNPs are proposed. An <span class="hlt">Fe</span>-O-As structure was formed on Co<span class="hlt">Fe</span>2O4@MIL-100(<span class="hlt">Fe</span>) through hydroxyl substitution with the deprotonated iAs species. Monolayer adsorption of As(V) was observed, while hydrogen bonding led to the multi-layer adsorption of neutral As(III) for its high adsorption capacity. The high efficiency and the excellent pH- and interference-tolerance capacities of Co<span class="hlt">Fe</span>2O4@MIL-100(<span class="hlt">Fe</span>) allowed effective iAs removal from natural water samples, as <span class="hlt">validated</span> with batch magnetic separation mode and a portable filtration strategy. PMID:28102334</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatSR...740955Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatSR...740955Y"><span>Co<span class="hlt">Fe</span>2O4@MIL-100(<span class="hlt">Fe</span>) hybrid magnetic nanoparticles exhibit fast and selective adsorption of arsenic with high adsorption capacity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Ji-Chun; Yin, Xue-Bo</p> <p>2017-01-01</p> <p>In this study, we report the synthesis and application of mesoporous Co<span class="hlt">Fe</span>2O4@MIL-100(<span class="hlt">Fe</span>) hybrid magnetic nanoparticles (MNPs) for the simultaneous removal of inorganic arsenic (iAs). The hybrid adsorbent had a core-shell and mesoporous structure with an average diameter of 260 nm. The nanoscale size and mesoporous character impart a fast adsorption rate and high adsorption capacity for iAs. In total, 0.1 mg L-1 As(V) and As(III) could be adsorbed within 2 min, and the maximum adsorption capacities were 114.8 mg g-1 for As(V) and 143.6 mg g-1 for As(III), higher than most previously reported adsorbents. The anti-interference capacity for iAs adsorption was improved by the electrostatic repulsion and size exclusion effects of the MIL-100(<span class="hlt">Fe</span>) shell, which also decreased the zero-charge point of the hybrid absorbent for a broad pH adsorption range. The adsorption mechanisms of iAs on the MNPs are proposed. An <span class="hlt">Fe</span>-O-As structure was formed on Co<span class="hlt">Fe</span>2O4@MIL-100(<span class="hlt">Fe</span>) through hydroxyl substitution with the deprotonated iAs species. Monolayer adsorption of As(V) was observed, while hydrogen bonding led to the multi-layer adsorption of neutral As(III) for its high adsorption capacity. The high efficiency and the excellent pH- and interference-tolerance capacities of Co<span class="hlt">Fe</span>2O4@MIL-100(<span class="hlt">Fe</span>) allowed effective iAs removal from natural water samples, as <span class="hlt">validated</span> with batch magnetic separation mode and a portable filtration strategy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4701248','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4701248"><span>A <span class="hlt">Model</span>-Based Approach to Support <span class="hlt">Validation</span> of Medical Cyber-Physical Systems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Silva, Lenardo C.; Almeida, Hyggo O.; Perkusich, Angelo; Perkusich, Mirko</p> <p>2015-01-01</p> <p>Medical Cyber-Physical Systems (MCPS) are context-aware, life-critical systems with patient safety as the main concern, demanding rigorous processes for <span class="hlt">validation</span> to guarantee user requirement compliance and specification-oriented correctness. In this article, we propose a <span class="hlt">model</span>-based approach for early <span class="hlt">validation</span> of MCPS, focusing on promoting reusability and productivity. It enables system developers to build MCPS formal <span class="hlt">models</span> based on a library of patient and medical device <span class="hlt">models</span>, and simulate the MCPS to identify undesirable behaviors at design time. Our approach has been applied to three different clinical scenarios to evaluate its reusability potential for different contexts. We have also <span class="hlt">validated</span> our approach through an empirical evaluation with developers to assess productivity and reusability. Finally, our <span class="hlt">models</span> have been formally verified considering functional and safety requirements and <span class="hlt">model</span> coverage. PMID:26528982</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26528982','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26528982"><span>A <span class="hlt">Model</span>-Based Approach to Support <span class="hlt">Validation</span> of Medical Cyber-Physical Systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Silva, Lenardo C; Almeida, Hyggo O; Perkusich, Angelo; Perkusich, Mirko</p> <p>2015-10-30</p> <p>Medical Cyber-Physical Systems (MCPS) are context-aware, life-critical systems with patient safety as the main concern, demanding rigorous processes for <span class="hlt">validation</span> to guarantee user requirement compliance and specification-oriented correctness. In this article, we propose a <span class="hlt">model</span>-based approach for early <span class="hlt">validation</span> of MCPS, focusing on promoting reusability and productivity. It enables system developers to build MCPS formal <span class="hlt">models</span> based on a library of patient and medical device <span class="hlt">models</span>, and simulate the MCPS to identify undesirable behaviors at design time. Our approach has been applied to three different clinical scenarios to evaluate its reusability potential for different contexts. We have also <span class="hlt">validated</span> our approach through an empirical evaluation with developers to assess productivity and reusability. Finally, our <span class="hlt">models</span> have been formally verified considering functional and safety requirements and <span class="hlt">model</span> coverage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1210133-thermal-stability-intermetallic-phases-fe-rich-fe-cr-ni-mo-alloys','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1210133-thermal-stability-intermetallic-phases-fe-rich-fe-cr-ni-mo-alloys"><span>Thermal stability of intermetallic phases in <span class="hlt">Fe</span>-rich <span class="hlt">Fe</span>-Cr-Ni-Mo alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Yang, Ying; Tan, Lizhen; Busby, Jeremy T.</p> <p>2015-06-12</p> <p>Understanding the stability of precipitate phases in the <span class="hlt">Fe</span>-rich <span class="hlt">Fe</span>-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic <span class="hlt">modeling</span>, stability of the chi and Laves phases in two <span class="hlt">Fe</span>-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 °C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. The two key findings resulted from this work. One is that the chi phase is stable at high temperature and transformed intomore » the Laves phase at low temperature. The other is that both the chi and Laves phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic <span class="hlt">models</span> were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950024822','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950024822"><span>A process improvement <span class="hlt">model</span> for software verification and <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Callahan, John; Sabolish, George</p> <p>1994-01-01</p> <p>We describe ongoing work at the NASA Independent Verification and <span class="hlt">Validation</span> (IV&V) Facility to establish a process improvement <span class="hlt">model</span> for software verification and <span class="hlt">validation</span> (V&V) organizations. This <span class="hlt">model</span>, similar to those used by some software development organizations, uses measurement-based techniques to identify problem areas and introduce incremental improvements. We seek to replicate this <span class="hlt">model</span> for organizations involved in V&V on large-scale software development projects such as EOS and space station. At the IV&V Facility, a university research group and V&V contractors are working together to collect metrics across projects in order to determine the effectiveness of V&V and improve its application. Since V&V processes are intimately tied to development processes, this paper also examines the repercussions for development organizations in large-scale efforts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950020394','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950020394"><span>A process improvement <span class="hlt">model</span> for software verification and <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Callahan, John; Sabolish, George</p> <p>1994-01-01</p> <p>We describe ongoing work at the NASA Independent Verification and <span class="hlt">Validation</span> (IV&V) Facility to establish a process improvement <span class="hlt">model</span> for software verification and <span class="hlt">validation</span> (V&V) organizations. This <span class="hlt">model</span>, similar to those used by some software development organizations, uses measurement-based techniques to identify problem areas and introduce incremental improvements. We seek to replicate this <span class="hlt">model</span> for organizations involved in V&V on large-scale software development projects such as EOS and Space Station. At the IV&V Facility, a university research group and V&V contractors are working together to collect metrics across projects in order to determine the effectiveness of V&V and improve its application. Since V&V processes are intimately tied to development processes, this paper also examines the repercussions for development organizations in large-scale efforts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97n4105G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97n4105G"><span>Crystal-melt interface mobility in bcc <span class="hlt">Fe</span>: Linking molecular dynamics to phase-field and phase-field crystal <span class="hlt">modeling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guerdane, M.; Berghoff, M.</p> <p>2018-04-01</p> <p>By combining molecular dynamics (MD) simulations with phase-field (PF) and phase-field crystal (PFC) <span class="hlt">modeling</span> we study collision-controlled growth kinetics from the melt for pure <span class="hlt">Fe</span>. The MD/PF comparison shows, on the one hand, that the PF <span class="hlt">model</span> can be properly designed to reproduce quantitatively different aspects of the growth kinetics and anisotropy of planar and curved solid-liquid interfaces. On the other hand, this comparison demonstrates the ability of classical MD simulations to predict morphology and dynamics of moving curved interfaces up to a length scale of about 0.15 μ m . After mapping the MD <span class="hlt">model</span> to the PF one, the latter permits to analyze the separate contribution of different anisotropies to the interface morphology. The MD/PFC agreement regarding the growth anisotropy and morphology extends the trend already observed for the here used PFC <span class="hlt">model</span> in describing structural and elastic properties of bcc <span class="hlt">Fe</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1376519','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1376519"><span>Strong 3D and 1D magnetism in hexagonal <span class="hlt">Fe</span>-chalcogenides <span class="hlt">Fe</span>S and <span class="hlt">Fe</span>Se vs. weak magnetism in hexagonal <span class="hlt">Fe</span>Te</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Parker, David S.</p> <p>2017-06-13</p> <p>We present a comparative theoretical study of the hexagonal forms of the <span class="hlt">Fe</span>-chalcogenides <span class="hlt">Fe</span>S, <span class="hlt">Fe</span>Se and <span class="hlt">Fe</span>Te with their better known tetragonal forms. While the tetragonal forms exhibit only an incipient antiferromagnetism and experimentally show superconductivity when doped, the hexagonal forms of <span class="hlt">Fe</span>S and <span class="hlt">Fe</span>Se display a robust magnetism. We show that this strong magnetism arises from a van Hove singularity associated with the direct <span class="hlt">Fe-Fe</span> c-axis chains in the generally more three-dimensional NiAs structure. We also find that hexagonal <span class="hlt">Fe</span>Te is much less magnetic than the other two hexagonal materials, so that unconventional magnetically-mediated superconductivity is possible, although amore » large T c value is unlikely.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.4166G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.4166G"><span>The Space Weather <span class="hlt">Modeling</span> Framework (SWMF): <span class="hlt">Models</span> and <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gombosi, Tamas; Toth, Gabor; Sokolov, Igor; de Zeeuw, Darren; van der Holst, Bart; Ridley, Aaron; Manchester, Ward, IV</p> <p></p> <p>In the last decade our group at the Center for Space Environment <span class="hlt">Modeling</span> (CSEM) has developed the Space Weather <span class="hlt">Modeling</span> Framework (SWMF) that efficiently couples together different <span class="hlt">models</span> describing the interacting regions of the space environment. Many of these domain <span class="hlt">models</span> (such as the global solar corona, the inner heliosphere or the global magneto-sphere) are based on MHD and are represented by our multiphysics code, BATS-R-US. SWMF is a powerful tool for coupling regional <span class="hlt">models</span> describing the space environment from the solar photosphere to the bottom of the ionosphere. Presently, SWMF contains over a dozen components: the solar corona (SC), eruptive event generator (EE), inner heliosphere (IE), outer heliosphere (OH), solar energetic particles (SE), global magnetosphere (GM), inner magnetosphere (IM), radiation belts (RB), plasmasphere (PS), ionospheric electrodynamics (IE), polar wind (PW), upper atmosphere (UA) and lower atmosphere (LA). This talk will present an overview of SWMF, new results obtained with improved physics as well as some <span class="hlt">validation</span> studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050220692','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050220692"><span>CFD <span class="hlt">Modeling</span> Needs and What Makes a Good Supersonic Combustion <span class="hlt">Validation</span> Experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gaffney, Richard L., Jr.; Cutler, Andrew D.</p> <p>2005-01-01</p> <p>If a CFD code/<span class="hlt">model</span> developer is asked what experimental data he wants to <span class="hlt">validate</span> his code or numerical <span class="hlt">model</span>, his answer will be: "Everything, everywhere, at all times." Since this is not possible, practical, or even reasonable, the developer must understand what can be measured within the limits imposed by the test article, the test location, the test environment and the available diagnostic equipment. At the same time, it is important for the expermentalist/diagnostician to understand what the CFD developer needs (as opposed to wants) in order to conduct a useful CFD <span class="hlt">validation</span> experiment. If these needs are not known, it is possible to neglect easily measured quantities at locations needed by the developer, rendering the data set useless for <span class="hlt">validation</span> purposes. It is also important for the experimentalist/diagnostician to understand what the developer is trying to <span class="hlt">validate</span> so that the experiment can be designed to isolate (as much as possible) the effects of a particular physical phenomena that is associated with the <span class="hlt">model</span> to be <span class="hlt">validated</span>. The probability of a successful <span class="hlt">validation</span> experiment can be greatly increased if the two groups work together, each understanding the needs and limitations of the other.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5978242','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5978242"><span>Removal of Crystal Violet by Using Reduced-Graphene-Oxide-Supported Bimetallic <span class="hlt">Fe</span>/Ni Nanoparticles (rGO/<span class="hlt">Fe</span>/Ni): Application of Artificial Intelligence <span class="hlt">Modeling</span> for the Optimization Process</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ruan, Wenqian; Qi, Jimei; Hou, Yu; Cao, Rensheng; Wei, Xionghui</p> <p>2018-01-01</p> <p>Reduced-graphene-oxide-supported bimetallic <span class="hlt">Fe</span>/Ni nanoparticles were synthesized in this study for the removal of crystal violet (CV) dye from aqueous solutions. This material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), Raman spectroscopy, N2-sorption, and X-ray photoelectron spectroscopy (XPS). The influence of independent parameters (namely, initial dye concentration, initial pH, contact time, and temperature) on the removal efficiency were investigated via Box–Behnken design (BBD). Artificial intelligence (i.e., artificial neural network, genetic algorithm, and particle swarm optimization) was used to optimize and predict the optimum conditions and obtain the maximum removal efficiency. The zero point of charge (pHZPC) of rGO/<span class="hlt">Fe</span>/Ni composites was determined by using the salt addition method. The experimental equilibrium data were fitted well to the Freundlich <span class="hlt">model</span> for the evaluation of the actual behavior of CV adsorption, and the maximum adsorption capacity was estimated as 2000.00 mg/g. The kinetic study discloses that the adsorption processes can be satisfactorily described by the pseudo-second-order <span class="hlt">model</span>. The values of Gibbs free energy change (ΔG0), entropy change (ΔS0), and enthalpy change (ΔH0) demonstrate the spontaneous and endothermic nature of the adsorption of CV onto rGO/<span class="hlt">Fe</span>/Ni composites. PMID:29789483</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29789483','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29789483"><span>Removal of Crystal Violet by Using Reduced-Graphene-Oxide-Supported Bimetallic <span class="hlt">Fe</span>/Ni Nanoparticles (rGO/<span class="hlt">Fe</span>/Ni): Application of Artificial Intelligence <span class="hlt">Modeling</span> for the Optimization Process.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ruan, Wenqian; Hu, Jiwei; Qi, Jimei; Hou, Yu; Cao, Rensheng; Wei, Xionghui</p> <p>2018-05-22</p> <p>Reduced-graphene-oxide-supported bimetallic <span class="hlt">Fe</span>/Ni nanoparticles were synthesized in this study for the removal of crystal violet (CV) dye from aqueous solutions. This material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), Raman spectroscopy, N₂-sorption, and X-ray photoelectron spectroscopy (XPS). The influence of independent parameters (namely, initial dye concentration, initial pH, contact time, and temperature) on the removal efficiency were investigated via Box⁻Behnken design (BBD). Artificial intelligence (i.e., artificial neural network, genetic algorithm, and particle swarm optimization) was used to optimize and predict the optimum conditions and obtain the maximum removal efficiency. The zero point of charge (pH ZPC ) of rGO/<span class="hlt">Fe</span>/Ni composites was determined by using the salt addition method. The experimental equilibrium data were fitted well to the Freundlich <span class="hlt">model</span> for the evaluation of the actual behavior of CV adsorption, and the maximum adsorption capacity was estimated as 2000.00 mg/g. The kinetic study discloses that the adsorption processes can be satisfactorily described by the pseudo-second-order <span class="hlt">model</span>. The values of Gibbs free energy change (Δ G ⁰), entropy change (Δ S ⁰), and enthalpy change (Δ H ⁰) demonstrate the spontaneous and endothermic nature of the adsorption of CV onto rGO/<span class="hlt">Fe</span>/Ni composites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.V13E..02W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.V13E..02W"><span>Tracing mantle processes with <span class="hlt">Fe</span> isotopes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weyer, S.; Ionov, D.</p> <p>2006-12-01</p> <p>High precision <span class="hlt">Fe</span> isotope measurements have been performed on various mantle peridotites (fertile lherzolites, harzburgites, metasomatised <span class="hlt">Fe</span>-enriched rocks) and volcanic rocks (mainly oceanic basalts) from different localities and tectonic settings. Pimitive peridotites (Mg# = 0.894) yield delta56<span class="hlt">Fe</span> = 0.02 and are significantly lighter than the basalts (average delta56<span class="hlt">Fe</span> = 0.11). Furthermore, the peridotites display a negative correlation of iron isotopes with Mg#. Taken together, these findings imply that <span class="hlt">Fe</span> isotopes fractionate during partial melting, with heavy isotopes preferentially entering the melt [1, 2]. A particularly good correlation of the <span class="hlt">Fe</span> isotope composition and Mg# shown by poorly metasomatised spinel lherzolites of three localities (Horoman, Kamchatka and Lherz) was used to <span class="hlt">model</span> <span class="hlt">Fe</span> isotope fractionation during partial melting, resulting in alphamantle-melt = 1.0003. This value implies higher <span class="hlt">Fe</span> isotope fractionation between residual mantle and mantle-derived melts (i.e. Delta56Femantle-melt = 0.2-0.3) than the observed difference between the peridotites and the basalts in this study. Our data on plagioclase lherzolites from Horoman and spinel lherzolites from other localities indicate that the difference in <span class="hlt">Fe</span> isotope composition between mantle and basalts may be reduced by partial re-equilibration between the isotopically heavy basalts and the isotopically light depleted lithospheric mantle during melt ascent. Besides partial melting, the <span class="hlt">Fe</span> isotope composition of mantle peridotites can also be significantly modified by metasomatic events. At two localities (Tok, Siberia and Tariat, Mongolia) <span class="hlt">Fe</span> isotopes correlates with the <span class="hlt">Fe</span> concentration of the peridotites, which was increased up to 14.5% <span class="hlt">Fe</span>O by melt percolation. Such processes can be accompanied by chromatographic effects and produce a range of <span class="hlt">Fe</span> isotope compositions in the percolation columns, from extremely light to heavy (delta56<span class="hlt">Fe</span> = -0.42 to +0.17). We propose that <span class="hlt">Fe</span> isotopes can be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=268749','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=268749"><span>Influence of <span class="hlt">Fe</span>EDDS, <span class="hlt">Fe</span>EDTA, <span class="hlt">Fe</span>DTPA, <span class="hlt">Fe</span>EDDHA, and <span class="hlt">Fe</span>SO4 on Marigold Growth and Nutrition, and Substrate and Runoff Chemistry</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Objectives of the study were to determine effects of <span class="hlt">Fe</span> source on plant growth, plant nutrition, substrate chemistry and runoff chemistry. Iron source (FS) treatments consisted of <span class="hlt">Fe</span>-aminopolycarboxylic acid (APCA) complexones iron ethylenediaminetetraacetic acid (<span class="hlt">Fe</span>EDTA), iron [S, S']-ethylenediam...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1048750','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1048750"><span>Improved Healing of Large, Osseous, Segmental Defects by Reverse Dynamization: Evaluation in a Sheep <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2017-12-01</p> <p>reverse dynamization. This was supplemented by finite element analysis and the use of a strain gauge. This aim was successfully completed, with the...testing deformation results for <span class="hlt">model</span> <span class="hlt">validation</span>. Development of a Finite Element (<span class="hlt">FE</span>) <span class="hlt">model</span> was conducted through ANSYS 16 to help characterize...Fixators were characterized through mechanical testing by sawbone and ovine cadaver tibiae samples, and data was used to <span class="hlt">validate</span> a finite element</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70185175','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70185175"><span>Mechanisms for <span class="hlt">Fe</span>(III) oxide reduction in sedimentary environments</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nevin, Kelly P.; Lovely, Derek R.</p> <p>2002-01-01</p> <p>Although it was previously considered that <span class="hlt">Fe</span>(III)-reducing microorganisms must come into direct contact with <span class="hlt">Fe</span>(III) oxides in order to reduce them, recent studies have suggested that electron-shuttling compounds and/or <span class="hlt">Fe</span>(III) chelators, either naturally present or produced by the <span class="hlt">Fe</span>(III)-reducing microorganisms themselves, may alleviate the need for the <span class="hlt">Fe</span>(III) reducers to establish direct contact with <span class="hlt">Fe</span>(III) oxides. Studies with Shewanella alga strain BrY and <span class="hlt">Fe</span>(III) oxides sequestered within microporous beads demonstrated for the first time that this organism releases a compound(s) that permits electron transfer to <span class="hlt">Fe</span>(III) oxides which the organism cannot directly contact. Furthermore, as much as 450 w M dissolved <span class="hlt">Fe</span>(III) was detected in cultures of S. alga growing in <span class="hlt">Fe</span>(III) oxide medium, suggesting that this organism releases compounds that can solublize <span class="hlt">Fe</span>(III) from <span class="hlt">Fe</span>(III) oxide. These results contrast with previous studies, which demonstrated that Geobacter metallireducens does not produce electron-shuttles or <span class="hlt">Fe</span>(III) chelators. Some freshwater aquatic sediments and groundwaters contained compounds, which could act as electron shuttles by accepting electrons from G. metallireducens and then transferring the electrons to <span class="hlt">Fe</span>(III). However, other samples lacked significant electron-shuttling capacity. Spectroscopic studies indicated that the electron-shuttling capacity of the waters was not only associated with the presence of humic substances, but water extracts of walnut, oak, and maple leaves contained electron-shuttling compounds did not appear to be humic substances. Porewater from a freshwater aquatic sediment and groundwater from a petroleum-contaminated aquifer contained dissolved <span class="hlt">Fe</span>(III) (4-16 w M), suggesting that soluble <span class="hlt">Fe</span>(III) may be available as an electron acceptor in some sedimentary environments. These results demonstrate that in order to accurately <span class="hlt">model</span> the mechanisms for <span class="hlt">Fe</span>(III) reduction in sedimentary environments it will be necessary</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25361792','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25361792"><span>Community-Based Participatory Research Conceptual <span class="hlt">Model</span>: Community Partner Consultation and Face <span class="hlt">Validity</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Belone, Lorenda; Lucero, Julie E; Duran, Bonnie; Tafoya, Greg; Baker, Elizabeth A; Chan, Domin; Chang, Charlotte; Greene-Moton, Ella; Kelley, Michele A; Wallerstein, Nina</p> <p>2016-01-01</p> <p>A national community-based participatory research (CBPR) team developed a conceptual <span class="hlt">model</span> of CBPR partnerships to understand the contribution of partnership processes to improved community capacity and health outcomes. With the <span class="hlt">model</span> primarily developed through academic literature and expert consensus building, we sought community input to assess face <span class="hlt">validity</span> and acceptability. Our research team conducted semi-structured focus groups with six partnerships nationwide. Participants <span class="hlt">validated</span> and expanded on existing <span class="hlt">model</span> constructs and identified new constructs based on "real-world" praxis, resulting in a revised <span class="hlt">model</span>. Four cross-cutting constructs were identified: trust development, capacity, mutual learning, and power dynamics. By empirically testing the <span class="hlt">model</span>, we found community face <span class="hlt">validity</span> and capacity to adapt the <span class="hlt">model</span> to diverse contexts. We recommend partnerships use and adapt the CBPR <span class="hlt">model</span> and its constructs, for collective reflection and evaluation, to enhance their partnering practices and achieve their health and research goals. © The Author(s) 2014.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140009153','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140009153"><span>KINEROS2-AGWA: <span class="hlt">Model</span> Use, Calibration, and <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goodrich, D C.; Burns, I. S.; Unkrich, C. L.; Semmens, D. J.; Guertin, D. P.; Hernandez, M.; Yatheendradas, S.; Kennedy, J. R.; Levick, L. R..</p> <p>2013-01-01</p> <p>KINEROS (KINematic runoff and EROSion) originated in the 1960s as a distributed event-based <span class="hlt">model</span> that conceptualizes a watershed as a cascade of overland flow <span class="hlt">model</span> elements that flow into trapezoidal channel <span class="hlt">model</span> elements. KINEROS was one of the first widely available watershed <span class="hlt">models</span> that interactively coupled a finite difference approximation of the kinematic overland flow equations to a physically based infiltration <span class="hlt">model</span>. Development and improvement of KINEROS continued from the 1960s on a variety of projects for a range of purposes, which has resulted in a suite of KINEROS-based <span class="hlt">modeling</span> tools. This article focuses on KINEROS2 (K2), a spatially distributed, event-based watershed rainfall-runoff and erosion <span class="hlt">model</span>, and the companion ArcGIS-based Automated Geospatial Watershed Assessment (AGWA) tool. AGWA automates the time-consuming tasks of watershed delineation into distributed <span class="hlt">model</span> elements and initial parameterization of these elements using commonly available, national GIS data layers. A variety of approaches have been used to calibrate and <span class="hlt">validate</span> K2 successfully across a relatively broad range of applications (e.g., urbanization, pre- and post-fire, hillslope erosion, erosion from roads, runoff and recharge, and manure transport). The case studies presented in this article (1) compare lumped to stepwise calibration and <span class="hlt">validation</span> of runoff and sediment at plot, hillslope, and small watershed scales; and (2) demonstrate an uncalibrated application to address relative change in watershed response to wildfire.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70191700','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70191700"><span>KINEROS2/AGWA: <span class="hlt">Model</span> use, calibration and <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Goodrich, D.C.; Burns, I.S.; Unkrich, C.L.; Semmens, Darius J.; Guertin, D.P.; Hernandez, M.; Yatheendradas, S.; Kennedy, Jeffrey R.; Levick, Lainie R.</p> <p>2012-01-01</p> <p>KINEROS (KINematic runoff and EROSion) originated in the 1960s as a distributed event-based <span class="hlt">model</span> that conceptualizes a watershed as a cascade of overland flow <span class="hlt">model</span> elements that flow into trapezoidal channel <span class="hlt">model</span> elements. KINEROS was one of the first widely available watershed <span class="hlt">models</span> that interactively coupled a finite difference approximation of the kinematic overland flow equations to a physically based infiltration <span class="hlt">model</span>. Development and improvement of KINEROS continued from the 1960s on a variety of projects for a range of purposes, which has resulted in a suite of KINEROS-based <span class="hlt">modeling</span> tools. This article focuses on KINEROS2 (K2), a spatially distributed, event-based watershed rainfall-runoff and erosion <span class="hlt">model</span>, and the companion ArcGIS-based Automated Geospatial Watershed Assessment (AGWA) tool. AGWA automates the time-consuming tasks of watershed delineation into distributed <span class="hlt">model</span> elements and initial parameterization of these elements using commonly available, national GIS data layers. A variety of approaches have been used to calibrate and <span class="hlt">validate</span> K2 successfully across a relatively broad range of applications (e.g., urbanization, pre- and post-fire, hillslope erosion, erosion from roads, runoff and recharge, and manure transport). The case studies presented in this article (1) compare lumped to stepwise calibration and <span class="hlt">validation</span> of runoff and sediment at plot, hillslope, and small watershed scales; and (2) demonstrate an uncalibrated application to address relative change in watershed response to wildfire.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/39612','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/39612"><span><span class="hlt">Validation</span> of elk resource selection <span class="hlt">models</span> with spatially independent data</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Priscilla K. Coe; Bruce K. Johnson; Michael J. Wisdom; John G. Cook; Marty Vavra; Ryan M. Nielson</p> <p>2011-01-01</p> <p>Knowledge of how landscape features affect wildlife resource use is essential for informed management. Resource selection functions often are used to make and <span class="hlt">validate</span> predictions about landscape use; however, resource selection functions are rarely <span class="hlt">validated</span> with data from landscapes independent of those from which the <span class="hlt">models</span> were built. This problem has severely...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......271S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......271S"><span>A <span class="hlt">validated</span> approach for <span class="hlt">modeling</span> collapse of steel structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saykin, Vitaliy Victorovich</p> <p></p> <p>A civil engineering structure is faced with many hazardous conditions such as blasts, earthquakes, hurricanes, tornadoes, floods, and fires during its lifetime. Even though structures are designed for credible events that can happen during a lifetime of the structure, extreme events do happen and cause catastrophic failures. Understanding the causes and effects of structural collapse is now at the core of critical areas of national need. One factor that makes studying structural collapse difficult is the lack of full-scale structural collapse experimental test results against which researchers could <span class="hlt">validate</span> their proposed collapse <span class="hlt">modeling</span> approaches. The goal of this work is the creation of an element deletion strategy based on fracture <span class="hlt">models</span> for use in <span class="hlt">validated</span> prediction of collapse of steel structures. The current work reviews the state-of-the-art of finite element deletion strategies for use in collapse <span class="hlt">modeling</span> of structures. It is shown that current approaches to element deletion in collapse <span class="hlt">modeling</span> do not take into account stress triaxiality in vulnerable areas of the structure, which is important for proper fracture and element deletion <span class="hlt">modeling</span>. The report then reviews triaxiality and its role in fracture prediction. It is shown that fracture in ductile materials is a function of triaxiality. It is also shown that, depending on the triaxiality range, different fracture mechanisms are active and should be accounted for. An approach using semi-empirical fracture <span class="hlt">models</span> as a function of triaxiality are employed. The <span class="hlt">models</span> to determine fracture initiation, softening and subsequent finite element deletion are outlined. This procedure allows for stress-displacement softening at an integration point of a finite element in order to subsequently remove the element. This approach avoids abrupt changes in the stress that would create dynamic instabilities, thus making the results more reliable and accurate. The calibration and <span class="hlt">validation</span> of these <span class="hlt">models</span> are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21750601','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21750601"><span>Nonparametric <span class="hlt">model</span> <span class="hlt">validations</span> for hidden Markov <span class="hlt">models</span> with applications in financial econometrics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, Zhibiao</p> <p>2011-06-01</p> <p>We address the nonparametric <span class="hlt">model</span> <span class="hlt">validation</span> problem for hidden Markov <span class="hlt">models</span> with partially observable variables and hidden states. We achieve this goal by constructing a nonparametric simultaneous confidence envelope for transition density function of the observable variables and checking whether the parametric density estimate is contained within such an envelope. Our specification test procedure is motivated by a functional connection between the transition density of the observable variables and the Markov transition kernel of the hidden states. Our approach is applicable for continuous time diffusion <span class="hlt">models</span>, stochastic volatility <span class="hlt">models</span>, nonlinear time series <span class="hlt">models</span>, and <span class="hlt">models</span> with market microstructure noise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3132196','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3132196"><span>Nonparametric <span class="hlt">model</span> <span class="hlt">validations</span> for hidden Markov <span class="hlt">models</span> with applications in financial econometrics</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhao, Zhibiao</p> <p>2011-01-01</p> <p>We address the nonparametric <span class="hlt">model</span> <span class="hlt">validation</span> problem for hidden Markov <span class="hlt">models</span> with partially observable variables and hidden states. We achieve this goal by constructing a nonparametric simultaneous confidence envelope for transition density function of the observable variables and checking whether the parametric density estimate is contained within such an envelope. Our specification test procedure is motivated by a functional connection between the transition density of the observable variables and the Markov transition kernel of the hidden states. Our approach is applicable for continuous time diffusion <span class="hlt">models</span>, stochastic volatility <span class="hlt">models</span>, nonlinear time series <span class="hlt">models</span>, and <span class="hlt">models</span> with market microstructure noise. PMID:21750601</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.C54A..02P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.C54A..02P"><span>A Historical Forcing Ice Sheet <span class="hlt">Model</span> <span class="hlt">Validation</span> Framework for Greenland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Price, S. F.; Hoffman, M. J.; Howat, I. M.; Bonin, J. A.; Chambers, D. P.; Kalashnikova, I.; Neumann, T.; Nowicki, S.; Perego, M.; Salinger, A.</p> <p>2014-12-01</p> <p>We propose an ice sheet <span class="hlt">model</span> testing and <span class="hlt">validation</span> framework for Greenland for the years 2000 to the present. Following Perego et al. (2014), we start with a realistic ice sheet initial condition that is in quasi-equilibrium with climate forcing from the late 1990's. This initial condition is integrated forward in time while simultaneously applying (1) surface mass balance forcing (van Angelen et al., 2013) and (2) outlet glacier flux anomalies, defined using a new dataset of Greenland outlet glacier flux for the past decade (Enderlin et al., 2014). <span class="hlt">Modeled</span> rates of mass and elevation change are compared directly to remote sensing observations obtained from GRACE and ICESat. Here, we present a detailed description of the proposed <span class="hlt">validation</span> framework including the ice sheet <span class="hlt">model</span> and <span class="hlt">model</span> forcing approach, the <span class="hlt">model</span>-to-observation comparison process, and initial results comparing <span class="hlt">model</span> output and observations for the time period 2000-2013.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930021499','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930021499"><span><span class="hlt">Validation</span> and upgrading of physically based mathematical <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Duval, Ronald</p> <p>1992-01-01</p> <p>The <span class="hlt">validation</span> of the results of physically-based mathematical <span class="hlt">models</span> against experimental results was discussed. Systematic techniques are used for: (1) isolating subsets of the simulator mathematical <span class="hlt">model</span> and comparing the response of each subset to its experimental response for the same input conditions; (2) evaluating the response error to determine whether it is the result of incorrect parameter values, incorrect structure of the <span class="hlt">model</span> subset, or unmodeled external effects of cross coupling; and (3) modifying and upgrading the <span class="hlt">model</span> and its parameter values to determine the most physically appropriate combination of changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010047674','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010047674"><span>Experimental <span class="hlt">Validation</span> of a Thermoelastic <span class="hlt">Model</span> for SMA Hybrid Composites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Turner, Travis L.</p> <p>2001-01-01</p> <p>This study presents results from experimental <span class="hlt">validation</span> of a recently developed <span class="hlt">model</span> for predicting the thermomechanical behavior of shape memory alloy hybrid composite (SMAHC) structures, composite structures with an embedded SMA constituent. The <span class="hlt">model</span> captures the material nonlinearity of the material system with temperature and is capable of <span class="hlt">modeling</span> constrained, restrained, or free recovery behavior from experimental measurement of fundamental engineering properties. A brief description of the <span class="hlt">model</span> and analysis procedures is given, followed by an overview of a parallel effort to fabricate and characterize the material system of SMAHC specimens. Static and dynamic experimental configurations for the SMAHC specimens are described and experimental results for thermal post-buckling and random response are presented. Excellent agreement is achieved between the measured and predicted results, fully <span class="hlt">validating</span> the theoretical <span class="hlt">model</span> for constrained recovery behavior of SMAHC structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1009290','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1009290"><span>Improved Conceptual <span class="hlt">Models</span> Methodology (ICoMM) for <span class="hlt">Validation</span> of Non-Observable Systems</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-12-01</p> <p>distribution is unlimited IMPROVED CONCEPTUAL <span class="hlt">MODELS</span> METHODOLOGY (ICoMM) FOR <span class="hlt">VALIDATION</span> OF NON-OBSERVABLE SYSTEMS by Sang M. Sok December 2015...REPORT TYPE AND DATES COVERED Dissertation 4. TITLE AND SUBTITLE IMPROVED CONCEPTUAL <span class="hlt">MODELS</span> METHODOLOGY (ICoMM) FOR <span class="hlt">VALIDATION</span> OF NON-OBSERVABLE...importance of the CoM. The improved conceptual <span class="hlt">model</span> methodology (ICoMM) is developed in support of improving the structure of the CoM for both face and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EPJA...50...55W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EPJA...50...55W"><span>Study on the keV neutron capture reaction in 56<span class="hlt">Fe</span> and 57<span class="hlt">Fe</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Taofeng; Lee, Manwoo; Kim, Guinyun; Ro, Tae-Ik; Kang, Yeong-Rok; Igashira, Masayuki; Katabuchi, Tatsuya</p> <p>2014-03-01</p> <p>The neutron capture cross-sections and the radiative capture gamma-ray spectra from the broad resonances of 56<span class="hlt">Fe</span> and 57<span class="hlt">Fe</span> in the neutron energy range from 10 to 90keV and 550keV have been measured with an anti-Compton NaI(Tl) detector. Pulsed keV neutrons were produced from the 7Li 7Be reaction by bombarding the lithium target with the 1.5ns bunched proton beam from the 3MV Pelletron accelerator. The incident neutron spectrum on a capture sample was measured by means of a time-of-flight (TOF) method with a 6Li -glass detector. The number of weighted capture counts of the iron or gold sample was obtained by applying a pulse height weighting technique to the corresponding capture gamma-ray pulse height spectrum. The neutron capture gamma-ray spectra were obtained by unfolding the observed capture gamma-ray pulse height spectra. To achieve further understanding on the mechanism of neutron radiative capture reaction and study on physics <span class="hlt">models</span>, theoretical calculations of the -ray spectra for 56<span class="hlt">Fe</span> and 57<span class="hlt">Fe</span> with the POD program have been performed by applying the Hauser-Feshbach statistical <span class="hlt">model</span>. The dominant ingredients to perform the statistical calculation were the Optical <span class="hlt">Model</span> Potential (OMP), the level densities described by the Mengoni-Nakajima approach, and the -ray transmission coefficients described by -ray strength functions. The comparison of the theoretical calculations, performed only for the 550keV point, show a good agreement with the present experimental results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Icar..307..172R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Icar..307..172R"><span>Top-down freezing in a <span class="hlt">Fe-Fe</span>S core and Ganymede's present-day magnetic field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rückriemen, Tina; Breuer, Doris; Spohn, Tilman</p> <p>2018-06-01</p> <p>Ganymede's core most likely possesses an active dynamo today, which produces a magnetic field at the surface of ∼ 719 nT. Thermochemical convection triggered by cooling of the core is a feasible power source for the dynamo. Experiments of different research groups indicate low pressure gradients of the melting temperatures for <span class="hlt">Fe-Fe</span>S core alloys at pressures prevailing in Ganymede's core ( < 10 GPa). This may entail that the core crystallizes from the top instead of from the bottom as is expected for Earth's core. Depending on the core sulfur concentration being more iron- or more sulfur-rich than the eutectic concentration either snowing iron crystals or a solid <span class="hlt">Fe</span>S layer can form at the top of the core. We investigate whether these two core crystallization scenarios are capable of explaining Ganymede's present magnetic activity. To do so, we set up a parametrized one-dimensional thermal evolution <span class="hlt">model</span>. We explore a wide range of parameters by running a large set of Monte Carlo simulations. Both freezing scenarios can explain Ganymede's present-day magnetic field. Dynamos of iron snow <span class="hlt">models</span> are rather young ( < 1 Gyr), whereas dynamos below the <span class="hlt">Fe</span>S layer can be both young and much older ( ∼ 3.8 Gyr). Successful <span class="hlt">models</span> preferably contain less radiogenic heat sources in the mantle than the chondritic abundance and show a correlation between the reference viscosity in the mantle and the initial core sulfur concentration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22606282-dopant-concentration-dependent-growth-fe-zno-nanostructures','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22606282-dopant-concentration-dependent-growth-fe-zno-nanostructures"><span>Dopant concentration dependent growth of <span class="hlt">Fe</span>:ZnO nanostructures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Sahai, Anshuman; Goswami, Navendu, E-mail: navendugoswami@gmail.com</p> <p>2016-05-23</p> <p>Systematic investigations of structural properties of 1-10% <span class="hlt">Fe</span> doped ZnO nanostructure (<span class="hlt">Fe</span>:ZnO NS) prepared via chemical precipitation method have been reported. Structural properties were probed thoroughly employing scanning electron microscope (SEM) and transmission electron microscope (TEM), energy dispersive X-ray (EDAX) analysis and X-ray diffraction (XRD). Morphological transformation of nanostructures (NS) with <span class="hlt">Fe</span> incorporation is evident in SEM/TEM images. Nanoparticles (NP) obtained with 1% <span class="hlt">Fe</span>, evolve to nanorods (NR) for 3% <span class="hlt">Fe</span>; NR transform to nanocones (NC) (for 5% and 7% <span class="hlt">Fe</span>) and finally NC transform to nanoflakes (NF) at 10% <span class="hlt">Fe</span>. Morover, primary phase of Zn{sub 1-x}<span class="hlt">Fe</span>{sub x}O along withmore » secondary phases of Zn<span class="hlt">Fe</span>{sub 2}O{sub 4} and <span class="hlt">Fe</span>{sub 2}O{sub 3} were also revealed through XRD measurements. Based on collective XRD, SEM, TEM, and EDAX interpretations, a <span class="hlt">model</span> for morphological evolution of NS was proposed and the pivotal role of <span class="hlt">Fe</span> dopant was deciphered.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22617229-statistical-theory-diffusion-concentrated-bcc-fcc-alloys-concentration-dependencies-diffusion-coefficients-bcc-alloys-fecu-femn-feni-fecr','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22617229-statistical-theory-diffusion-concentrated-bcc-fcc-alloys-concentration-dependencies-diffusion-coefficients-bcc-alloys-fecu-femn-feni-fecr"><span>Statistical theory of diffusion in concentrated bcc and fcc alloys and concentration dependencies of diffusion coefficients in bcc alloys <span class="hlt">Fe</span>Cu, <span class="hlt">Fe</span>Mn, <span class="hlt">Fe</span>Ni, and <span class="hlt">Fe</span>Cr</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Vaks, V. G.; Khromov, K. Yu., E-mail: khromov-ky@nrcki.ru; Pankratov, I. R.</p> <p>2016-07-15</p> <p>The statistical theory of diffusion in concentrated bcc and fcc alloys with arbitrary pairwise interatomic interactions based on the master equation approach is developed. Vacancy–atom correlations are described using both the second-shell-jump and the nearest-neighbor-jump approximations which are shown to be usually sufficiently accurate. General expressions for Onsager coefficients in terms of microscopic interatomic interactions and some statistical averages are given. Both the analytical kinetic mean-field and the Monte Carlo methods for finding these averages are described. The theory developed is used to describe sharp concentration dependencies of diffusion coefficients in several iron-based alloy systems. For the bcc alloys <span class="hlt">Fe</span>Cu,more » <span class="hlt">Fe</span>Mn, and <span class="hlt">Fe</span>Ni, we predict the notable increase of the iron self-diffusion coefficient with solute concentration c, up to several times, even though values of c possible for these alloys do not exceed some percent. For the bcc alloys <span class="hlt">Fe</span>Cr at high temperatures T ≳ 1400 K, we show that the very strong and peculiar concentration dependencies of both tracer and chemical diffusion coefficients observed in these alloys can be naturally explained by the theory, without invoking exotic <span class="hlt">models</span> discussed earlier.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.8131K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.8131K"><span><span class="hlt">Fe</span>-Distribution and Hydrogen Generation During Serpentinization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klein, F.; Bach, W.; Jöns, N.; McCollom, T.; Berquó, T.; Moskowitz, B.</p> <p>2009-04-01</p> <p>Serpentinization of peridotite generates large amounts of dihydrogen (H2,aq), indicated by the presence of Ni-<span class="hlt">Fe</span> alloys and low-sulfur-fugacity sulfides, e. g. awaruite and pentlandite, in serpentinites. Hydrogen is produced when ferrous iron in olivine is oxidized by water to ferric iron in secondary magnetite and serpentine. This process is strongly dependent on bulk rock composition, water-to-rock ratio and temperature. These relations were examined in thermodynamic reaction path <span class="hlt">models</span> (using the EQ3/6 computer code) with dunitic and harzburgitic rock compositions. The <span class="hlt">model</span> results were compared with electron microprobe analyses, bulk magnetization measurements, and Mößbauer spectroscopy of partially to fully serpentinized dunites and harzburgites from Ocean Drilling Program Leg 209, Hole 1274A, Mid-Atlantic Ridge 15 °N. These samples have mesh rims that reveal a distinct in-to-out zoning, starting with brucite (Mg# 80) at the interface with olivine, then a zone of serpentine (Mg# 95) + brucite ± magnetite, and finally serpentine + magnetite in the outermost mesh rim. The composition of co-existing serpentine and brucite in pseudomorphic mesh rims is virtually constant in most samples from 32 to 147 meters below seafloor, suggesting similar alteration conditions of olivine downhole. Bulk magnetization measurements of microdrilled mesh rims in combination with thin section petrography revealed a positive correlation of magnetite content with extent of serpentinization. Where relic olivine is present, the magnetite content is significantly lower then in fully serpentinized rocks. In these domains with sparse magnetite, Mößbauer spectra revealed <span class="hlt">Fe</span>3+/ <span class="hlt">Fe</span> values between 0.30 and 0.48 for paramagnetic minerals in the mesh rims (i. e., secondary hydrous phases). In heavily to completely serpentinized rocks with abundant magnetite, <span class="hlt">Fe</span>3+/ <span class="hlt">Fe</span> values of the paramagnetic phases are consistently higher and range from 0.53 to 0.68. In the EQ3/6 runs, a serpentine</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4590912','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4590912"><span><span class="hlt">Validation</span> of the Continuum of Care Conceptual <span class="hlt">Model</span> for Athletic Therapy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lafave, Mark R.; Butterwick, Dale; Eubank, Breda</p> <p>2015-01-01</p> <p>Utilization of conceptual <span class="hlt">models</span> in field-based emergency care currently borrows from existing standards of medical and paramedical professions. The purpose of this study was to develop and <span class="hlt">validate</span> a comprehensive conceptual <span class="hlt">model</span> that could account for injuries ranging from nonurgent to catastrophic events including events that do not follow traditional medical or prehospital care protocols. The conceptual <span class="hlt">model</span> should represent the continuum of care from the time of initial injury spanning to an athlete's return to participation in their sport. Finally, the conceptual <span class="hlt">model</span> should accommodate both novices and experts in the AT profession. This paper chronicles the content <span class="hlt">validation</span> steps of the Continuum of Care Conceptual <span class="hlt">Model</span> for Athletic Therapy (CCCM-AT). The stages of <span class="hlt">model</span> development were domain and item generation, content expert <span class="hlt">validation</span> using a three-stage modified Ebel procedure, and pilot testing. Only the final stage of the modified Ebel procedure reached a priori 80% consensus on three domains of interest: (1) heading descriptors; (2) the order of the <span class="hlt">model</span>; (3) the conceptual <span class="hlt">model</span> as a whole. Future research is required to test the use of the CCCM-AT in order to understand its efficacy in teaching and practice within the AT discipline. PMID:26464897</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1170703','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1170703"><span>Verifying and <span class="hlt">Validating</span> Simulation <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hemez, Francois M.</p> <p>2015-02-23</p> <p>This presentation is a high-level discussion of the Verification and <span class="hlt">Validation</span> (V&V) of computational <span class="hlt">models</span>. Definitions of V&V are given to emphasize that “validation” is never performed in a vacuum; it accounts, instead, for the current state-of-knowledge in the discipline considered. In particular comparisons between physical measurements and numerical predictions should account for their respective sources of uncertainty. The differences between error (bias), aleatoric uncertainty (randomness) and epistemic uncertainty (ignorance, lack-of- knowledge) are briefly discussed. Four types of uncertainty in physics and engineering are discussed: 1) experimental variability, 2) variability and randomness, 3) numerical uncertainty and 4) <span class="hlt">model</span>-form uncertainty. Statisticalmore » sampling methods are available to propagate, and analyze, variability and randomness. Numerical uncertainty originates from the truncation error introduced by the discretization of partial differential equations in time and space. <span class="hlt">Model</span>-form uncertainty is introduced by assumptions often formulated to render a complex problem more tractable and amenable to <span class="hlt">modeling</span> and simulation. The discussion concludes with high-level guidance to assess the “credibility” of numerical simulations, which stems from the level of rigor with which these various sources of uncertainty are assessed and quantified.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApSS..434.1266G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApSS..434.1266G"><span>MIL-100-<span class="hlt">Fe</span> derived N-doped <span class="hlt">Fe/Fe</span>3C@C electrocatalysts for efficient oxygen reduction reaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, Dakai; Han, Sancan; Wang, Jiacheng; Zhu, Yufang</p> <p>2018-03-01</p> <p>N-doped porous <span class="hlt">Fe/Fe</span>3C@C electrocatalysts were prepared by the pyrolysis of the hexamethylenetetramine (HMT)-incorporated MIL-100-<span class="hlt">Fe</span> at different temperatures (700-1000 °C) under N2 atmosphere. Rotary evaporation of MIL-100-<span class="hlt">Fe</span> and HMT solution could make more N-enriched HMT molecules enter into the pores of MIL-100-<span class="hlt">Fe</span>, thus improving nitrogen contents of the final pyrolyzed samples. All pyrolyzed samples show porous textures with middle specific surface areas. The X-ray photoelectron spectroscopy (XPS) results demonstrate the successful introduction of N atoms into carbon framework. Sample <span class="hlt">Fe</span>-N2-800 prepared by annealing the precursors with the HMT/MIL-100-<span class="hlt">Fe</span> weight ratio of 2 at 800 °C exhibits the best electrocatalytic activity towards the oxygen reduction reaction (ORR) in terms of onset potential and current density because of high graphitic N and pyridinic N content. The enwrapped <span class="hlt">Fe/Fe</span>3C nanoparticles and <span class="hlt">Fe</span>-Nx active sites in these samples could also boost the ORR activity synergistically. Moreover, sample <span class="hlt">Fe</span>-N2-800 demonstrates a dominant four electron reduction process, as well as excellent long-term operation stability and methanol crossover resistance. Thus, the N-doped <span class="hlt">Fe/Fe</span>3C@C composites derived from the HMT-incorporated MIL-100-<span class="hlt">Fe</span> are promising electrocatalysts to replace Pt/C for ORR in practical applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/3478','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/3478"><span>I-15 San Diego, California, <span class="hlt">model</span> <span class="hlt">validation</span> and calibration report.</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>2010-02-01</p> <p>The Integrated Corridor Management (ICM) initiative requires the calibration and <span class="hlt">validation</span> of simulation <span class="hlt">models</span> used in the Analysis, <span class="hlt">Modeling</span>, and Simulation of Pioneer Site proposed integrated corridors. This report summarizes the results and proc...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29738795','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29738795"><span>Animal <span class="hlt">models</span> of binge drinking, current challenges to improve face <span class="hlt">validity</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jeanblanc, Jérôme; Rolland, Benjamin; Gierski, Fabien; Martinetti, Margaret P; Naassila, Mickael</p> <p>2018-05-05</p> <p>Binge drinking (BD), i.e., consuming a large amount of alcohol in a short period of time, is an increasing public health issue. Though no clear definition has been adopted worldwide the speed of drinking seems to be a keystone of this behavior. Developing relevant animal <span class="hlt">models</span> of BD is a priority for gaining a better characterization of the neurobiological and psychobiological mechanisms underlying this dangerous and harmful behavior. Until recently, preclinical research on BD has been conducted mostly using forced administration of alcohol, but more recent studies used scheduled access to alcohol, to <span class="hlt">model</span> more voluntary excessive intakes, and to achieve signs of intoxications that mimic the human behavior. The main challenges for future research are discussed regarding the need of good face <span class="hlt">validity</span>, construct <span class="hlt">validity</span> and predictive <span class="hlt">validity</span> of animal <span class="hlt">models</span> of BD. Copyright © 2018 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120007505','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120007505"><span>Techniques for Down-Sampling a Measured Surface Height Map for <span class="hlt">Model</span> <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sidick, Erkin</p> <p>2012-01-01</p> <p>This software allows one to down-sample a measured surface map for <span class="hlt">model</span> <span class="hlt">validation</span>, not only without introducing any re-sampling errors, but also eliminating the existing measurement noise and measurement errors. The software tool of the current two new techniques can be used in all optical <span class="hlt">model</span> <span class="hlt">validation</span> processes involving large space optical surfaces</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1399340','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1399340"><span><span class="hlt">Validation</span> Assessment of a Glass-to-Metal Seal Finite-Element <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jamison, Ryan Dale; Buchheit, Thomas E.; Emery, John M</p> <p></p> <p>Sealing glasses are ubiquitous in high pressure and temperature engineering applications, such as hermetic feed-through electrical connectors. A common connector technology are glass-to-metal seals where a metal shell compresses a sealing glass to create a hermetic seal. Though finite-element analysis has been used to understand and design glass-to-metal seals for many years, there has been little <span class="hlt">validation</span> of these <span class="hlt">models</span>. An indentation technique was employed to measure the residual stress on the surface of a simple glass-to-metal seal. Recently developed rate- dependent material <span class="hlt">models</span> of both Schott 8061 and 304L VAR stainless steel have been applied to a finite-element modelmore » of the simple glass-to-metal seal. <span class="hlt">Model</span> predictions of residual stress based on the evolution of material <span class="hlt">models</span> are shown. These <span class="hlt">model</span> predictions are compared to measured data. <span class="hlt">Validity</span> of the finite- element predictions is discussed. It will be shown that the finite-element <span class="hlt">model</span> of the glass-to-metal seal accurately predicts the mean residual stress in the glass near the glass-to-metal interface and is <span class="hlt">valid</span> for this quantity of interest.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15844447','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15844447"><span>External <span class="hlt">validation</span> of EPIWIN biodegradation <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Posthumus, R; Traas, T P; Peijnenburg, W J G M; Hulzebos, E M</p> <p>2005-01-01</p> <p>The BIOWIN biodegradation <span class="hlt">models</span> were evaluated for their suitability for regulatory purposes. BIOWIN includes the linear and non-linear BIODEG and MITI <span class="hlt">models</span> for estimating the probability of rapid aerobic biodegradation and an expert survey <span class="hlt">model</span> for primary and ultimate biodegradation estimation. Experimental biodegradation data for 110 newly notified substances were compared with the estimations of the different <span class="hlt">models</span>. The <span class="hlt">models</span> were applied separately and in combinations to determine which <span class="hlt">model(s</span>) showed the best performance. The results of this study were compared with the results of other <span class="hlt">validation</span> studies and other biodegradation <span class="hlt">models</span>. The BIOWIN <span class="hlt">models</span> predict not-readily biodegradable substances with high accuracy in contrast to ready biodegradability. In view of the high environmental concern of persistent chemicals and in view of the large number of not-readily biodegradable chemicals compared to the readily ones, a <span class="hlt">model</span> is preferred that gives a minimum of false positives without a corresponding high percentage false negatives. A combination of the BIOWIN <span class="hlt">models</span> (BIOWIN2 or BIOWIN6) showed the highest predictive value for not-readily biodegradability. However, the highest score for overall predictivity with lowest percentage false predictions was achieved by applying BIOWIN3 (pass level 2.75) and BIOWIN6.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1869f0004S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1869f0004S"><span>Experimental <span class="hlt">validation</span> of prototype high voltage bushing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shah, Sejal; Tyagi, H.; Sharma, D.; Parmar, D.; M. N., Vishnudev; Joshi, K.; Patel, K.; Yadav, A.; Patel, R.; Bandyopadhyay, M.; Rotti, C.; Chakraborty, A.</p> <p>2017-08-01</p> <p>Prototype High voltage bushing (PHVB) is a scaled down configuration of DNB High Voltage Bushing (HVB) of ITER. It is designed for operation at 50 kV DC to ensure operational performance and thereby confirming the design configuration of DNB HVB. Two concentric insulators viz. Ceramic and Fiber reinforced polymer (FRP) rings are used as double layered vacuum boundary for 50 kV isolation between grounded and high voltage flanges. Stress shields are designed for smooth electric field distribution. During ceramic to Kovar brazing, spilling cannot be controlled which may lead to high localized electrostatic stress. To understand spilling phenomenon and precise stress calculation, quantitative analysis was performed using Scanning Electron Microscopy (SEM) of brazed sample and similar configuration <span class="hlt">modeled</span> while performing the Finite Element (<span class="hlt">FE</span>) analysis. <span class="hlt">FE</span> analysis of PHVB is performed to find out electrical stresses on different areas of PHVB and are maintained similar to DNB HV Bushing. With this configuration, the experiment is performed considering ITER like vacuum and electrical parameters. Initial HV test is performed by temporary vacuum sealing arrangements using gaskets/O-rings at both ends in order to achieve desired vacuum and keep the system maintainable. During <span class="hlt">validation</span> test, 50 kV voltage withstand is performed for one hour. Voltage withstand test for 60 kV DC (20% higher rated voltage) have also been performed without any breakdown. Successful operation of PHVB confirms the design of DNB HV Bushing. In this paper, configuration of PHVB with experimental <span class="hlt">validation</span> data is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SurSc.640..159Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SurSc.640..159Y"><span>Reaction pathways of <span class="hlt">model</span> compounds of biomass-derived oxygenates on <span class="hlt">Fe</span>/Ni bimetallic surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Weiting; Chen, Jingguang G.</p> <p>2015-10-01</p> <p>Controlling the activity and selectivity of converting biomass-derivatives to fuels and valuable chemicals is critical for the utilization of biomass feedstocks. There are primarily three classes of non-food competing biomass, cellulose, hemicellulose and lignin. In the current work, glycolaldehyde, furfural and acetaldehyde are studied as <span class="hlt">model</span> compounds of the three classes of biomass-derivatives. Monometallic Ni(111) and monolayer (ML) <span class="hlt">Fe</span>/Ni(111) bimetallic surfaces are studied for the reaction pathways of the three biomass surrogates. The ML <span class="hlt">Fe</span>/Ni(111) surface is identified as an efficient surface for the conversion of biomass-derivatives from the combined results of density functional theory (DFT) calculations and temperature programmed desorption (TPD) experiments. A correlation is also established between the optimized adsorption geometry and experimental reaction pathways. These results should provide helpful insights in catalyst design for the upgrading and conversion of biomass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MRE.....3j5603L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MRE.....3j5603L"><span>Removal of Cd2+ and Cu2+ ions from aqueous solution by using <span class="hlt">Fe-Fe</span>3O4/graphene oxide as a novel and efficient adsorbent</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Le, Giang H.; Ha, Anh Q.; Nguyen, Quang K.; Nguyen, Kien T.; Dang, Phuong T.; Tran, Hoa T. K.; Vu, Loi D.; Nguyen, Tuyen V.; Lee, Gun D.; Vu, Tuan A.</p> <p>2016-10-01</p> <p>The nano <span class="hlt">Fe-Fe</span>3O4/graphene oxide (GO) was successfully synthesized by the precipitation method and followed by chemical reduction using <span class="hlt">Fe</span>Cl3 as iron sources and NaBH4 as reducing agent. The products were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), BET, x-ray photoelectron spectroscopy (XPS) and VMS. From the obtained XRD and XPS results, it revealed the formation of both <span class="hlt">Fe</span> and <span class="hlt">Fe</span>3O4 nano particles on GO surface. TEM images showed that both <span class="hlt">Fe</span>3O4/GO and <span class="hlt">Fe-Fe</span>3O4/GO had small particle size of 10-20 nm and uniform size distribution. <span class="hlt">Fe</span>3O4/GO and <span class="hlt">Fe-Fe</span>3O4/GO were used as adsorbents for removal of Cd2+ and Cu2+ ions from aqueous solution. Maximum adsorption capacity (Q max) of <span class="hlt">Fe-Fe</span>3O4/GO for Cu2+ and Cd2+ are 90.0 mg g-1 and 108.6 mg g-1, respectively. These values are much higher as compared to those of <span class="hlt">Fe</span>3O4/GO as well as those reported in the literature. Additionally, this novel adsorbent can be reused by washing with diluted Hcl solution and easily recovered by applying the magnetic field. The Cd2+ adsorption isotherm fits better for the Langmuir <span class="hlt">model</span> that of the Freundlich <span class="hlt">model</span> and it obeys the pseudo-second order kinetic equation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26385050','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26385050"><span>Ventilation tube insertion simulation: a literature review and <span class="hlt">validity</span> assessment of five training <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mahalingam, S; Awad, Z; Tolley, N S; Khemani, S</p> <p>2016-08-01</p> <p>The objective of this study was to identify and investigate the face and content <span class="hlt">validity</span> of ventilation tube insertion (VTI) training <span class="hlt">models</span> described in the literature. A review of literature was carried out to identify articles describing VTI simulators. Feasible <span class="hlt">models</span> were replicated and assessed by a group of experts. Postgraduate simulation centre. Experts were defined as surgeons who had performed at least 100 VTI on patients. Seventeen experts were participated ensuring sufficient statistical power for analysis. A standardised 18-item Likert-scale questionnaire was used. This addressed face <span class="hlt">validity</span> (realism), global and task-specific content (suitability of the <span class="hlt">model</span> for teaching) and curriculum recommendation. The search revealed eleven <span class="hlt">models</span>, of which only five had associated <span class="hlt">validity</span> data. Five <span class="hlt">models</span> were found to be feasible to replicate. None of the tested <span class="hlt">models</span> achieved face or global content <span class="hlt">validity</span>. Only one <span class="hlt">model</span> achieved task-specific <span class="hlt">validity</span>, and hence, there was no agreement on curriculum recommendation. The quality of simulation <span class="hlt">models</span> is moderate and there is room for improvement. There is a need for new <span class="hlt">models</span> to be developed or existing ones to be refined in order to construct a more realistic training platform for VTI simulation. © 2015 John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1702p0005B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1702p0005B"><span>Non-linear heterogeneous <span class="hlt">FE</span> approach for FRP strengthened masonry arches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bertolesi, Elisa; Milani, Gabriele; Fedele, Roberto</p> <p>2015-12-01</p> <p>A fast and reliable non-linear heterogeneous <span class="hlt">FE</span> approach specifically conceived for the analysis of FRP-reinforced masonry arches is presented. The approach proposed relies into the reduction of mortar joints to interfaces exhibiting a non-linear holonomic behavior, with a discretization of bricks by means of four-noded elastic elements. The FRP reinforcement is <span class="hlt">modeled</span> by means of truss elements with elastic-brittle behavior, where the peak tensile strength is estimated by means of a consolidated approach provided by the Italian guidelines CNR-DT200 on masonry strengthening with fiber materials, where the delamination of the strip from the support is taken into account. The <span class="hlt">model</span> is <span class="hlt">validated</span> against some recent experimental results relying into circular masonry arches reinforced at both the intrados and the extrados. Some sensitivity analyses are conducted varying the peak tensile strength of the trusses representing the FRP reinforcement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SSCom.269...90H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SSCom.269...90H"><span>Prediction on electronic structure of CH3NH3PbI3/<span class="hlt">Fe</span>3O4 interfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hou, Xueyao; Wang, Xiaocha; Mi, Wenbo; Du, Zunfeng</p> <p>2018-01-01</p> <p>The interfacial electronic structures of CH3NH3PbI3(MAPbI3)/<span class="hlt">Fe</span>3O4 heterostructures are predicted by density functional theory. Four <span class="hlt">models</span> (MAI/<span class="hlt">Fe</span>BO, PbI2/<span class="hlt">Fe</span>BO, MAI/<span class="hlt">Fe</span>A and PbI2/<span class="hlt">Fe</span>A) are included. Especially, a half-metal to semiconductor transition of <span class="hlt">Fe</span>3O4 appears in PbI2/<span class="hlt">Fe</span>A <span class="hlt">model</span>. A series of electric field is added to PbI2/<span class="hlt">Fe</span>A <span class="hlt">model</span>, and a direct-indirect bandgap transition of <span class="hlt">Fe</span>3O4 appears at a 500-kV/cm field. The electric field can control the bandgap of <span class="hlt">Fe</span>3O4 in PbI2/<span class="hlt">Fe</span>A <span class="hlt">model</span> by modulating the hybridization. The prediction of spin-related bandgap characteristic in MAPbI3/<span class="hlt">Fe</span>3O4 is meaningful for further study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED563402.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED563402.pdf"><span>A <span class="hlt">Validity</span> Agenda for Growth <span class="hlt">Models</span>: One Size Doesn't Fit All!</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Patelis, Thanos</p> <p>2012-01-01</p> <p>This is a keynote presentation given at AERA on developing a <span class="hlt">validity</span> agenda for growth <span class="hlt">models</span> in a large scale (e.g., state) setting. The emphasis of this presentation was to indicate that growth <span class="hlt">models</span> and the <span class="hlt">validity</span> agenda designed to provide evidence in supporting the claims to be made need to be personalized to meet the local or…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT........37M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT........37M"><span>Improvements to constitutive material <span class="hlt">model</span> for fabrics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morea, Mihai I.</p> <p>2011-12-01</p> <p>The high strength to weight ratio of woven fabric offers a cost effective solution to be used in a containment system for aircraft propulsion engines. Currently, Kevlar is the only Federal Aviation Administration (FAA) approved fabric for usage in systems intended to mitigate fan blade-out events. This research builds on an earlier constitutive <span class="hlt">model</span> of Kevlar 49 fabric developed at Arizona State University (ASU) with the addition of new and improved <span class="hlt">modeling</span> details. Latest stress strain experiments provided new and valuable data used to modify the material <span class="hlt">model</span> post peak behavior. These changes reveal an overall improvement of the Finite Element (<span class="hlt">FE</span>) <span class="hlt">model</span>'s ability to predict experimental results. First, the steel projectile is <span class="hlt">modeled</span> using Johnson-Cook material <span class="hlt">model</span> and provides a more realistic behavior in the <span class="hlt">FE</span> ballistic <span class="hlt">models</span>. This is particularly noticeable when comparing <span class="hlt">FE</span> <span class="hlt">models</span> with laboratory tests where large deformations in projectiles are observed. Second, follow-up analysis of the results obtained through the new picture frame tests conducted at ASU provides new values for the shear moduli and corresponding strains. The new approach for analysis of data from picture frame tests combines digital image analysis and a two-level factorial optimization formulation. Finally, an additional improvement in the material <span class="hlt">model</span> for Kevlar involves checking the convergence at variation of mesh density of fabrics. The study performed and described herein shows the converging trend, therefore <span class="hlt">validating</span> the <span class="hlt">FE</span> <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhyC..549...61W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhyC..549...61W"><span><span class="hlt">Fe</span>-vacancy and superconductivity in <span class="hlt">Fe</span>Se-based superconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, C. H.; Chen, T. K.; Chang, C. C.; Lee, Y. C.; Wang, M. J.; Huang, K. C.; Wu, P. M.; Wu, M. K.</p> <p>2018-06-01</p> <p>This review summarizes recent advancements in <span class="hlt">Fe</span>Se and related systems. The <span class="hlt">Fe</span>Se and related superconductors are currently receiving considerable attention for the high Tcs observed and for many similar features to the high Tc cuprate superconductors. These similarities suggest that understanding the <span class="hlt">Fe</span>Se based compounds could potentially help our understanding of the cuprates. We shall first review the common features observed in the <span class="hlt">Fe</span>Se-based system. It was found that with a careful control of material synthesizing processes, numerous rich phases have been observed in the <span class="hlt">Fe</span>Se-based system. Detailed studies show that the <span class="hlt">Fe</span>-vacancy ordered phases found in the <span class="hlt">Fe</span>Se based compounds, which are non-superconducting Mott insulators, are the parent compounds of the superconductors. Superconductivity emerges from the parent phases by disordering the <span class="hlt">Fe</span> vacancy order, often by a simple annealing treatment. Recent high temperature X-ray diffraction experiments show that the degree of structural distortion associated with the disorder of <span class="hlt">Fe</span>-vacancy is closely related to volume fraction of the superconductivity observed. These results suggest the strong lattice to spin coupling are important for the occurrence of superconductivity in <span class="hlt">Fe</span>Se based superconductors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMMM..451..193P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMMM..451..193P"><span>Interface spins in polycrystalline <span class="hlt">FeMn/Fe</span> bilayers with small exchange bias</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pires, M. J. M.</p> <p>2018-04-01</p> <p>The magnetic moments at the interface between ferromagnetic and antiferromagnetic layers play a central role in exchange biased systems, but their behavior is still not completely understood. In this work, the <span class="hlt">FeMn/Fe</span> interface in polycrystalline thin films has been studied using conversion electron Mössbauer spectroscopy (CEMS), magneto-optic Kerr effect (MOKE) and micromagnetic simulations. Samples were prepared with 57<span class="hlt">Fe</span> layers at two distinct depths in order to probe the interface and bulk behaviors. At the equilibrium, the interface moments are randomly oriented while the bulk of the <span class="hlt">Fe</span> layer has an in-plane magnetic anisotropy. Several <span class="hlt">models</span> for the interface and anisotropies of the layers were used in the simulations of spin configurations and hysteresis loops. From the whole set of simulations, one can conclude the direct analysis of hysteresis curves is not enough to infer whether the interface has a configuration with spins tilted out of the film plane at equilibrium since different choices of parameters provide similar curves. The simulations have also shown the occurrence of spin clusters at the interface is compatible with CEMS and MOKE measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26896316','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26896316"><span>Characterization of <span class="hlt">Fe</span> (III)-reducing enrichment culture and isolation of <span class="hlt">Fe</span> (III)-reducing bacterium Enterobacter sp. L6 from marine sediment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Hongyan; Wang, Hongyu</p> <p>2016-07-01</p> <p>To enrich the <span class="hlt">Fe</span> (III)-reducing bacteria, sludge from marine sediment was inoculated into the medium using <span class="hlt">Fe</span> (OH)3 as the sole electron acceptor. Efficiency of <span class="hlt">Fe</span> (III) reduction and composition of <span class="hlt">Fe</span> (III)-reducing enrichment culture were analyzed. The results indicated that the <span class="hlt">Fe</span> (III)-reducing enrichment culture with the dominant bacteria relating to Clostridium and Enterobacter sp. had high <span class="hlt">Fe</span> (III) reduction of (2.73 ± 0.13) mmol/L-<span class="hlt">Fe</span> (II). A new <span class="hlt">Fe</span> (III)-reducing bacterium was isolated from the <span class="hlt">Fe</span> (III)-reducing enrichment culture and identified as Enterobacter sp. L6 by 16S rRNA gene sequence analysis. The <span class="hlt">Fe</span> (III)-reducing ability of strain L6 under different culture conditions was investigated. The results indicated that strain L6 had high <span class="hlt">Fe</span> (III)-reducing activity using glucose and pyruvate as carbon sources. Strain L6 could reduce <span class="hlt">Fe</span> (III) at the range of NaCl concentrations tested and had the highest <span class="hlt">Fe</span> (III) reduction of (4.63 ± 0.27) mmol/L <span class="hlt">Fe</span> (II) at the NaCl concentration of 4 g/L. This strain L6 could reduce <span class="hlt">Fe</span> (III) with unique properties in adaptability to salt variation, which indicated that it can be used as a <span class="hlt">model</span> organism to study <span class="hlt">Fe</span> (III)-reducing activity isolated from marine environment. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4232048','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4232048"><span>Objective <span class="hlt">validation</span> of central sensitization in the rat UVB and heat rekindling <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Weerasinghe, NS; Lumb, BM; Apps, R; Koutsikou, S; Murrell, JC</p> <p>2014-01-01</p> <p>Background The UVB and heat rekindling (UVB/HR) <span class="hlt">model</span> shows potential as a translatable inflammatory pain <span class="hlt">model</span>. However, the occurrence of central sensitization in this <span class="hlt">model</span>, a fundamental mechanism underlying chronic pain, has been debated. Face, construct and predictive <span class="hlt">validity</span> are key requisites of animal <span class="hlt">models</span>; electromyogram (EMG) recordings were utilized to objectively demonstrate <span class="hlt">validity</span> of the rat UVB/HR <span class="hlt">model</span>. Methods The UVB/HR <span class="hlt">model</span> was induced on the heel of the hind paw under anaesthesia. Mechanical withdrawal thresholds (MWTs) were obtained from biceps femoris EMG responses to a gradually increasing pinch at the mid hind paw region under alfaxalone anaesthesia, 96 h after UVB irradiation. MWT was compared between UVB/HR and SHAM-treated rats (anaesthetic only). Underlying central mechanisms in the <span class="hlt">model</span> were pharmacologically <span class="hlt">validated</span> by MWT measurement following intrathecal N-methyl-d-aspartate (NMDA) receptor antagonist, MK-801, or saline. Results Secondary hyperalgesia was confirmed by a significantly lower pre-drug MWT {mean [±standard error of the mean (SEM)]} in UVB/HR [56.3 (±2.1) g/mm2, n = 15] compared with SHAM-treated rats [69.3 (±2.9) g/mm2, n = 8], confirming face <span class="hlt">validity</span> of the <span class="hlt">model</span>. Predictive <span class="hlt">validity</span> was demonstrated by the attenuation of secondary hyperalgesia by MK-801, where mean (±SEM) MWT was significantly higher [77.2 (±5.9) g/mm2 n = 7] in comparison with pre-drug [57.8 (±3.5) g/mm2 n = 7] and saline [57.0 (±3.2) g/mm2 n = 8] at peak drug effect. The occurrence of central sensitization confirmed construct <span class="hlt">validity</span> of the UVB/HR <span class="hlt">model</span>. Conclusions This study used objective outcome measures of secondary hyperalgesia to <span class="hlt">validate</span> the rat UVB/HR <span class="hlt">model</span> as a translational <span class="hlt">model</span> of inflammatory pain. What's already known about this topic? Most current animal chronic pain <span class="hlt">models</span> lack translatability to human subjects. Primary hyperalgesia is an established feature of the UVB/heat rekindling</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16464642','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16464642"><span><span class="hlt">Validation</span> by simulation of a clinical trial <span class="hlt">model</span> using the standardized mean and variance criteria.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abbas, Ismail; Rovira, Joan; Casanovas, Josep</p> <p>2006-12-01</p> <p>To develop and <span class="hlt">validate</span> a <span class="hlt">model</span> of a clinical trial that evaluates the changes in cholesterol level as a surrogate marker for lipodystrophy in HIV subjects under alternative antiretroviral regimes, i.e., treatment with Protease Inhibitors vs. a combination of nevirapine and other antiretroviral drugs. Five simulation <span class="hlt">models</span> were developed based on different assumptions, on treatment variability and pattern of cholesterol reduction over time. The last recorded cholesterol level, the difference from the baseline, the average difference from the baseline and level evolution, are the considered endpoints. Specific <span class="hlt">validation</span> criteria based on a 10% minus or plus standardized distance in means and variances were used to compare the real and the simulated data. The <span class="hlt">validity</span> criterion was met by all <span class="hlt">models</span> for considered endpoints. However, only two <span class="hlt">models</span> met the <span class="hlt">validity</span> criterion when all endpoints were considered. The <span class="hlt">model</span> based on the assumption that within-subjects variability of cholesterol levels changes over time is the one that minimizes the <span class="hlt">validity</span> criterion, standardized distance equal to or less than 1% minus or plus. Simulation is a useful technique for calibration, estimation, and evaluation of <span class="hlt">models</span>, which allows us to relax the often overly restrictive assumptions regarding parameters required by analytical approaches. The <span class="hlt">validity</span> criterion can also be used to select the preferred <span class="hlt">model</span> for design optimization, until additional data are obtained allowing an external <span class="hlt">validation</span> of the <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110007820','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110007820"><span><span class="hlt">Validation</span> of Community <span class="hlt">Models</span>: 2. Development of a Baseline, Using the Wang-Sheeley-Arge <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>MacNeice, Peter</p> <p>2009-01-01</p> <p>This paper is the second in a series providing independent <span class="hlt">validation</span> of community <span class="hlt">models</span> of the outer corona and inner heliosphere. Here I present a comprehensive <span class="hlt">validation</span> of the Wang-Sheeley-Arge (WSA) <span class="hlt">model</span>. These results will serve as a baseline against which to compare the next generation of comparable forecasting <span class="hlt">models</span>. The WSA <span class="hlt">model</span> is used by a number of agencies to predict Solar wind conditions at Earth up to 4 days into the future. Given its importance to both the research and forecasting communities, it is essential that its performance be measured systematically and independently. I offer just such an independent and systematic <span class="hlt">validation</span>. I report skill scores for the <span class="hlt">model</span>'s predictions of wind speed and interplanetary magnetic field (IMF) polarity for a large set of Carrington rotations. The <span class="hlt">model</span> was run in all its routinely used configurations. It ingests synoptic line of sight magnetograms. For this study I generated <span class="hlt">model</span> results for monthly magnetograms from multiple observatories, spanning the Carrington rotation range from 1650 to 2074. I compare the influence of the different magnetogram sources and performance at quiet and active times. I also consider the ability of the WSA <span class="hlt">model</span> to forecast both sharp transitions in wind speed from slow to fast wind and reversals in the polarity of the radial component of the IMF. These results will serve as a baseline against which to compare future versions of the <span class="hlt">model</span> as well as the current and future generation of magnetohydrodynamic <span class="hlt">models</span> under development for forecasting use.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1177664-radiation-effects-interface-reactions-fe-fe+cr-fe+cr+ni','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1177664-radiation-effects-interface-reactions-fe-fe+cr-fe+cr+ni"><span>Radiation effects on interface reactions of U/<span class="hlt">Fe</span>, U/(<span class="hlt">Fe</span>+Cr), and U/(<span class="hlt">Fe</span>+Cr+Ni)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Shao, Lin; Chen, Di; Wei, Chaochen; ...</p> <p>2014-10-01</p> <p>We study the effects of radiation damage on interdiffusion and intermetallic phase formation at the interfaces of U/<span class="hlt">Fe</span>, U/(<span class="hlt">Fe</span> + Cr), and U/(<span class="hlt">Fe</span> + Cr + Ni) diffusion couples. Magnetron sputtering is used to deposit thin films of <span class="hlt">Fe</span>, <span class="hlt">Fe</span> + Cr, or <span class="hlt">Fe</span> + Cr + Ni on U substrates to form the diffusion couples. One set of samples are thermally annealed under high vacuum at 450 C or 550 C for one hour. A second set of samples are annealed identically but with concurrent 3.5 MeV <span class="hlt">Fe</span>++ ion irradiation. The <span class="hlt">Fe</span>++ ion penetration depth is sufficient to reachmore » the original interfaces. Rutherford backscattering spectrometry analysis with high fidelity spectral simulations is used to obtain interdiffusion profiles, which are used to examine differences in U diffusion and intermetallic phase formation at the buried interfaces. For all three diffusion systems, <span class="hlt">Fe</span>++ ion irradiations enhance U diffusion. Furthermore, the irradiations accelerate the formation of intermetallic phases. In U/<span class="hlt">Fe</span> couples, for example, the unirradiated samples show typical interdiffusion governed by Fick’s laws, while the irradiated ones show step-like profiles influenced by Gibbs phase rules.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JPCM...21S5402G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JPCM...21S5402G"><span><span class="hlt">Modeling</span> local structure using crystal field and spin Hamiltonian parameters: the tetragonal <span class="hlt">Fe</span>K3+-OI2- defect center in KTaO3 crystal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gnutek, P.; Y Yang, Z.; Rudowicz, C.</p> <p>2009-11-01</p> <p>The local structure and the spin Hamiltonian (SH) parameters, including the zero-field-splitting (ZFS) parameters D and (a+2F/3), and the Zeeman g factors g_{\\parallel } and g_{\\perp } , are theoretically investigated for the <span class="hlt">Fe</span>K3+-OI2- center in KTaO3 crystal. The microscopic SH (MSH) parameters are <span class="hlt">modeled</span> within the framework of the crystal field (CF) theory employing the CF analysis (CFA) package, which also incorporates the MSH modules. Our approach takes into account the spin-orbit interaction as well as the spin-spin and spin-other-orbit interactions omitted in previous studies. The superposition <span class="hlt">model</span> (SPM) calculations are carried out to provide input CF parameters for the CFA/MSH package. The combined SPM-CFA/MSH approach is used to consider various structural <span class="hlt">models</span> for the <span class="hlt">Fe</span>K3+-OI2- defect center in KTaO3. This <span class="hlt">modeling</span> reveals that the off-center displacement of the <span class="hlt">Fe</span>3+ ions, Δ1(<span class="hlt">Fe</span>3+), combined with an inward relaxation of the nearest oxygen ligands, Δ2(O2-), and the existence of the interstitial oxygen OI2- give rise to a strong tetragonal crystal field. This finding may explain the large ZFS experimentally observed for the <span class="hlt">Fe</span>K3+-OI2- center in KTaO3. Matching the theoretical MSH predictions with the available structural data as well as electron magnetic resonance (EMR) and optical spectroscopy data enables predicting reasonable ranges of values of Δ1(<span class="hlt">Fe</span>3+) and Δ2(O2-) as well as the possible location of OI2- ligands around <span class="hlt">Fe</span>3+ ions in KTaO3. The defect structure <span class="hlt">model</span> obtained using the SPM-CFA/MSH approach reproduces very well the ranges of the experimental SH parameters D, g_{\\parallel } and g_{\\perp } and importantly yields not only the correct magnitude of D but also the sign, unlike previous studies. More reliable predictions may be achieved when experimental data on (a+2F/3) and/or crystal field energy levels become available. Comparison of our results with those arising from alternative <span class="hlt">models</span> existing in the literature indicates</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1236916-isotopic-fractionation-associated-nife-fefe-hydrogenases','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1236916-isotopic-fractionation-associated-nife-fefe-hydrogenases"><span>Isotopic fractionation associated with [Ni<span class="hlt">Fe</span>]- and [<span class="hlt">FeFe</span>]-hydrogenases</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yang, Hui; Gandhi, Hasand; Cornish, Adam J.</p> <p>2016-01-30</p> <p>Hydrogenases catalyze the reversible formation of H2 from electrons and protons with high efficiency. Understanding the relationships between H2 production, H2 uptake, and H2-H2O exchange can provide insight into the metabolism of microbial communities in which H2 is an essential component in energy cycling. In this manuscript, we used stable H isotopes (1H and 2H) to probe the isotope effects associated with three [<span class="hlt">FeFe</span>]-hydrogenases and three [Ni<span class="hlt">Fe</span>]-hydrogenases. All six hydrogenases displayed fractionation factors for H2 formation that were significantly less than 1, producing H2 that was severely depleted in 2H relative to the substrate, water. Consistent with differences in theirmore » active site structure, the fractionation factors for each class appear to cluster, with the three [Ni<span class="hlt">Fe</span>]-hydrogenases (α = 0.27-0.40) generally having smaller values than the three [<span class="hlt">FeFe</span>]-hydrogenases (α = 0.41-0.55). We also obtained isotopic fractionation factors associated with H2 uptake and H2-H2O exchange under conditions similar to those utilized for H2 production, providing us with a more complete picture of the three reactions catalyzed by hydrogenases. The fractionation factors determined in our studies can be used as signatures for different hydrogenases to probe their activity under different growth conditions and to ascertain which hydrogenases are most responsible for H2 production and/or uptake in complex microbial communities.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25484028','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25484028"><span>Development and <span class="hlt">validation</span> of a cost-utility <span class="hlt">model</span> for Type 1 diabetes mellitus.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wolowacz, S; Pearson, I; Shannon, P; Chubb, B; Gundgaard, J; Davies, M; Briggs, A</p> <p>2015-08-01</p> <p>To develop a health economic <span class="hlt">model</span> to evaluate the cost-effectiveness of new interventions for Type 1 diabetes mellitus by their effects on long-term complications (measured through mean HbA1c ) while capturing the impact of treatment on hypoglycaemic events. Through a systematic review, we identified complications associated with Type 1 diabetes mellitus and data describing the long-term incidence of these complications. An individual patient simulation <span class="hlt">model</span> was developed and included the following complications: cardiovascular disease, peripheral neuropathy, microalbuminuria, end-stage renal disease, proliferative retinopathy, ketoacidosis, cataract, hypoglycemia and adverse birth outcomes. Risk equations were developed from published cumulative incidence data and hazard ratios for the effect of HbA1c , age and duration of diabetes. We <span class="hlt">validated</span> the <span class="hlt">model</span> by comparing <span class="hlt">model</span> predictions with observed outcomes from studies used to build the <span class="hlt">model</span> (internal <span class="hlt">validation</span>) and from other published data (external <span class="hlt">validation</span>). We performed illustrative analyses for typical patient cohorts and a hypothetical intervention. <span class="hlt">Model</span> predictions were within 2% of expected values in the internal <span class="hlt">validation</span> and within 8% of observed values in the external <span class="hlt">validation</span> (percentages represent absolute differences in the cumulative incidence). The <span class="hlt">model</span> utilized high-quality, recent data specific to people with Type 1 diabetes mellitus. In the <span class="hlt">model</span> <span class="hlt">validation</span>, results deviated less than 8% from expected values. © 2014 Research Triangle Institute d/b/a RTI Health Solutions. Diabetic Medicine © 2014 Diabetes UK.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ISPAn.II2a...1A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ISPAn.II2a...1A"><span>Towards Automatic <span class="hlt">Validation</span> and Healing of Citygml <span class="hlt">Models</span> for Geometric and Semantic Consistency</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alam, N.; Wagner, D.; Wewetzer, M.; von Falkenhausen, J.; Coors, V.; Pries, M.</p> <p>2013-09-01</p> <p>A steadily growing number of application fields for large 3D city <span class="hlt">models</span> have emerged in recent years. Like in many other domains, data quality is recognized as a key factor for successful business. Quality management is mandatory in the production chain nowadays. Automated domain-specific tools are widely used for <span class="hlt">validation</span> of business-critical data but still common standards defining correct geometric <span class="hlt">modeling</span> are not precise enough to define a sound base for data <span class="hlt">validation</span> of 3D city <span class="hlt">models</span>. Although the workflow for 3D city <span class="hlt">models</span> is well-established from data acquisition to processing, analysis and visualization, quality management is not yet a standard during this workflow. Processing data sets with unclear specification leads to erroneous results and application defects. We show that this problem persists even if data are standard compliant. <span class="hlt">Validation</span> results of real-world city <span class="hlt">models</span> are presented to demonstrate the potential of the approach. A tool to repair the errors detected during the <span class="hlt">validation</span> process is under development; first results are presented and discussed. The goal is to heal defects of the <span class="hlt">models</span> automatically and export a corrected CityGML <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JNuM..448...96B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JNuM..448...96B"><span>Application of a three-feature dispersed-barrier hardening <span class="hlt">model</span> to neutron-irradiated <span class="hlt">Fe</span>-Cr <span class="hlt">model</span> alloys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bergner, F.; Pareige, C.; Hernández-Mayoral, M.; Malerba, L.; Heintze, C.</p> <p>2014-05-01</p> <p>An attempt is made to quantify the contributions of different types of defect-solute clusters to the total irradiation-induced yield stress increase in neutron-irradiated (300 °C, 0.6 dpa), industrial-purity <span class="hlt">Fe</span>-Cr <span class="hlt">model</span> alloys (target Cr contents of 2.5, 5, 9 and 12 at.% Cr). Former work based on the application of transmission electron microscopy, atom probe tomography, and small-angle neutron scattering revealed the formation of dislocation loops, NiSiPCr-enriched clusters and α‧-phase particles, which act as obstacles to dislocation glide. The values of the dimensionless obstacle strength are estimated in the framework of a three-feature dispersed-barrier hardening <span class="hlt">model</span>. Special attention is paid to the effect of measuring errors, experimental details and <span class="hlt">model</span> details on the estimates. The three families of obstacles and the hardening <span class="hlt">model</span> are well capable of reproducing the observed yield stress increase as a function of Cr content, suggesting that the nanostructural features identified experimentally are the main, if not the only, causes of irradiation hardening in these <span class="hlt">model</span> alloys.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26987507','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26987507"><span>Modern <span class="hlt">modeling</span> techniques had limited external <span class="hlt">validity</span> in predicting mortality from traumatic brain injury.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van der Ploeg, Tjeerd; Nieboer, Daan; Steyerberg, Ewout W</p> <p>2016-10-01</p> <p>Prediction of medical outcomes may potentially benefit from using modern statistical <span class="hlt">modeling</span> techniques. We aimed to externally <span class="hlt">validate</span> <span class="hlt">modeling</span> strategies for prediction of 6-month mortality of patients suffering from traumatic brain injury (TBI) with predictor sets of increasing complexity. We analyzed individual patient data from 15 different studies including 11,026 TBI patients. We consecutively considered a core set of predictors (age, motor score, and pupillary reactivity), an extended set with computed tomography scan characteristics, and a further extension with two laboratory measurements (glucose and hemoglobin). With each of these sets, we predicted 6-month mortality using default settings with five statistical <span class="hlt">modeling</span> techniques: logistic regression (LR), classification and regression trees, random forests (RFs), support vector machines (SVM) and neural nets. For external <span class="hlt">validation</span>, a <span class="hlt">model</span> developed on one of the 15 data sets was applied to each of the 14 remaining sets. This process was repeated 15 times for a total of 630 <span class="hlt">validations</span>. The area under the receiver operating characteristic curve (AUC) was used to assess the discriminative ability of the <span class="hlt">models</span>. For the most complex predictor set, the LR <span class="hlt">models</span> performed best (median <span class="hlt">validated</span> AUC value, 0.757), followed by RF and support vector machine <span class="hlt">models</span> (median <span class="hlt">validated</span> AUC value, 0.735 and 0.732, respectively). With each predictor set, the classification and regression trees <span class="hlt">models</span> showed poor performance (median <span class="hlt">validated</span> AUC value, <0.7). The variability in performance across the studies was smallest for the RF- and LR-based <span class="hlt">models</span> (inter quartile range for <span class="hlt">validated</span> AUC values from 0.07 to 0.10). In the area of predicting mortality from TBI, nonlinear and nonadditive effects are not pronounced enough to make modern prediction methods beneficial. Copyright © 2016 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1850b0015U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1850b0015U"><span>Object-oriented simulation <span class="hlt">model</span> of a parabolic trough solar collector: Static and dynamic <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ubieta, Eduardo; Hoyo, Itzal del; Valenzuela, Loreto; Lopez-Martín, Rafael; Peña, Víctor de la; López, Susana</p> <p>2017-06-01</p> <p>A simulation <span class="hlt">model</span> of a parabolic-trough solar collector developed in Modelica® language is calibrated and <span class="hlt">validated</span>. The calibration is performed in order to approximate the behavior of the solar collector <span class="hlt">model</span> to a real one due to the uncertainty in some of the system parameters, i.e. measured data is used during the calibration process. Afterwards, the <span class="hlt">validation</span> of this calibrated <span class="hlt">model</span> is done. During the <span class="hlt">validation</span>, the results obtained from the <span class="hlt">model</span> are compared to the ones obtained during real operation in a collector from the Plataforma Solar de Almeria (PSA).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApJ...859..155B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApJ...859..155B"><span>The First Empirical Determination of the <span class="hlt">Fe</span>10+ and <span class="hlt">Fe</span>13+ Freeze-in Distances in the Solar Corona</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boe, Benjamin; Habbal, Shadia; Druckmüller, Miloslav; Landi, Enrico; Kourkchi, Ehsan; Ding, Adalbert; Starha, Pavel; Hutton, Joseph</p> <p>2018-06-01</p> <p>Heavy ions are markers of the physical processes responsible for the density and temperature distribution throughout the fine-scale magnetic structures that define the shape of the solar corona. One of their properties, whose empirical determination has remained elusive, is the “freeze-in” distance (R f ) where they reach fixed ionization states that are adhered to during their expansion with the solar wind. We present the first empirical inference of R f for {<span class="hlt">Fe</span>}}{10+} and {<span class="hlt">Fe</span>}}{13+} derived from multi-wavelength imaging observations of the corresponding <span class="hlt">Fe</span> XI ({<span class="hlt">Fe</span>}}{10+}) 789.2 nm and <span class="hlt">Fe</span> XIV ({<span class="hlt">Fe</span>}}{13+}) 530.3 nm emission acquired during the 2015 March 20 total solar eclipse. We find that the two ions freeze-in at different heliocentric distances. In polar coronal holes (CHs) R f is around 1.45 R ⊙ for {<span class="hlt">Fe</span>}}{10+} and below 1.25 R ⊙ for {<span class="hlt">Fe</span>}}{13+}. Along open field lines in streamer regions, R f ranges from 1.4 to 2 R ⊙ for {<span class="hlt">Fe</span>}}{10+} and from 1.5 to 2.2 R ⊙ for {<span class="hlt">Fe</span>}}{13+}. These first empirical R f values: (1) reflect the differing plasma parameters between CHs and streamers and structures within them, including prominences and coronal mass ejections; (2) are well below the currently quoted values derived from empirical <span class="hlt">model</span> studies; and (3) place doubt on the reliability of plasma diagnostics based on the assumption of ionization equilibrium beyond 1.2 R ⊙.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMMM..449..105L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMMM..449..105L"><span>A ferrofluid based energy harvester: Computational <span class="hlt">modeling</span>, analysis, and experimental <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Qi; Alazemi, Saad F.; Daqaq, Mohammed F.; Li, Gang</p> <p>2018-03-01</p> <p>A computational <span class="hlt">model</span> is described and implemented in this work to analyze the performance of a ferrofluid based electromagnetic energy harvester. The energy harvester converts ambient vibratory energy into an electromotive force through a sloshing motion of a ferrofluid. The computational <span class="hlt">model</span> solves the coupled Maxwell's equations and Navier-Stokes equations for the dynamic behavior of the magnetic field and fluid motion. The <span class="hlt">model</span> is <span class="hlt">validated</span> against experimental results for eight different configurations of the system. The <span class="hlt">validated</span> <span class="hlt">model</span> is then employed to study the underlying mechanisms that determine the electromotive force of the energy harvester. Furthermore, computational analysis is performed to test the effect of several <span class="hlt">modeling</span> aspects, such as three-dimensional effect, surface tension, and type of the ferrofluid-magnetic field coupling on the accuracy of the <span class="hlt">model</span> prediction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982iece.conf..544B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982iece.conf..544B"><span>Relaxation-phenomena in LiAl/<span class="hlt">Fe</span>S-cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borger, W.; Kappus, W.; Panesar, H. S.</p> <p></p> <p>A theoretical <span class="hlt">model</span> of the capacity of strongly relaxing electrochemical systems is applied to the LiAl/<span class="hlt">Fe</span>S system. Relaxation phenomena in LiAl and <span class="hlt">Fe</span>S electrodes can be described by this <span class="hlt">model</span>. Experimental relaxation data indicate that lithium transport through the alpha-LiAl layer to the particle surface is the capacity limiting process at high discharge current density in the LiAl electrode in LiCl-KCl and LiF-LiCl-LiBr mixtures. Strong relaxation is observed in the <span class="hlt">Fe</span>S electrode with LiCl-KCl electrolyte caused by lithium concentration gradients and precipitation of KCl in the pores.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120007375','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120007375"><span><span class="hlt">Model</span>-Based Method for Sensor <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vatan, Farrokh</p> <p>2012-01-01</p> <p>Fault detection, diagnosis, and prognosis are essential tasks in the operation of autonomous spacecraft, instruments, and in situ platforms. One of NASA s key mission requirements is robust state estimation. Sensing, using a wide range of sensors and sensor fusion approaches, plays a central role in robust state estimation, and there is a need to diagnose sensor failure as well as component failure. Sensor <span class="hlt">validation</span> can be considered to be part of the larger effort of improving reliability and safety. The standard methods for solving the sensor <span class="hlt">validation</span> problem are based on probabilistic analysis of the system, from which the method based on Bayesian networks is most popular. Therefore, these methods can only predict the most probable faulty sensors, which are subject to the initial probabilities defined for the failures. The method developed in this work is based on a <span class="hlt">model</span>-based approach and provides the faulty sensors (if any), which can be logically inferred from the <span class="hlt">model</span> of the system and the sensor readings (observations). The method is also more suitable for the systems when it is hard, or even impossible, to find the probability functions of the system. The method starts by a new mathematical description of the problem and develops a very efficient and systematic algorithm for its solution. The method builds on the concepts of analytical redundant relations (ARRs).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29843256','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29843256"><span>Developing a <span class="hlt">model</span> for hospital inherent safety assessment: Conceptualization and <span class="hlt">validation</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yari, Saeed; Akbari, Hesam; Gholami Fesharaki, Mohammad; Khosravizadeh, Omid; Ghasemi, Mohammad; Barsam, Yalda; Akbari, Hamed</p> <p>2018-01-01</p> <p>Paying attention to the safety of hospitals, as the most crucial institute for providing medical and health services wherein a bundle of facilities, equipment, and human resource exist, is of significant importance. The present research aims at developing a <span class="hlt">model</span> for assessing hospitals' safety based on principles of inherent safety design. Face <span class="hlt">validity</span> (30 experts), content <span class="hlt">validity</span> (20 experts), construct <span class="hlt">validity</span> (268 examples), convergent <span class="hlt">validity</span>, and divergent <span class="hlt">validity</span> have been employed to <span class="hlt">validate</span> the prepared questionnaire; and the items analysis, the Cronbach's alpha test, ICC test (to measure reliability of the test), composite reliability coefficient have been used to measure primary reliability. The relationship between variables and factors has been confirmed at 0.05 significance level by conducting confirmatory factor analysis (CFA) and structural equations <span class="hlt">modeling</span> (SEM) technique with the use of Smart-PLS. R-square and load factors values, which were higher than 0.67 and 0.300 respectively, indicated the strong fit. Moderation (0.970), simplification (0.959), substitution (0.943), and minimization (0.5008) have had the most weights in determining the inherent safety of hospital respectively. Moderation, simplification, and substitution, among the other dimensions, have more weight on the inherent safety, while minimization has the less weight, which could be due do its definition as to minimize the risk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJEEP..18....3J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJEEP..18....3J"><span>Load <span class="hlt">Model</span> Verification, <span class="hlt">Validation</span> and Calibration Framework by Statistical Analysis on Field Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiao, Xiangqing; Liao, Yuan; Nguyen, Thai</p> <p>2017-11-01</p> <p>Accurate load <span class="hlt">models</span> are critical for power system analysis and operation. A large amount of research work has been done on load <span class="hlt">modeling</span>. Most of the existing research focuses on developing load <span class="hlt">models</span>, while little has been done on developing formal load <span class="hlt">model</span> verification and <span class="hlt">validation</span> (V&V) methodologies or procedures. Most of the existing load <span class="hlt">model</span> <span class="hlt">validation</span> is based on qualitative rather than quantitative analysis. In addition, not all aspects of <span class="hlt">model</span> V&V problem have been addressed by the existing approaches. To complement the existing methods, this paper proposes a novel load <span class="hlt">model</span> verification and <span class="hlt">validation</span> framework that can systematically and more comprehensively examine load <span class="hlt">model</span>'s effectiveness and accuracy. Statistical analysis, instead of visual check, quantifies the load <span class="hlt">model</span>'s accuracy, and provides a confidence level of the developed load <span class="hlt">model</span> for <span class="hlt">model</span> users. The analysis results can also be used to calibrate load <span class="hlt">models</span>. The proposed framework can be used as a guidance to systematically examine load <span class="hlt">models</span> for utility engineers and researchers. The proposed method is demonstrated through analysis of field measurements collected from a utility system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030093709','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030093709"><span><span class="hlt">Modeling</span> of Iron K Lines: Radiative and Auger Decay Data for <span class="hlt">Fe</span> II-<span class="hlt">Fe</span> IX</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Palmeri, P.; Mendoza, C.; Kallman, T. R.; Bautista, M. A.; Melendez, M.</p> <p>2003-01-01</p> <p>A detailed analysis of the radiative and Auger de-excitation channels of K-shell vacancy states in <span class="hlt">Fe</span> II-<span class="hlt">Fe</span> IX has been carried out. Level energies, wavelengths, A-values, Auger rates and fluorescence yields have been calculated for the lowest fine-structure levels populated by photoionization of the ground state of the parent ion. Different branching ratios, namely K alpha 2/K alpha 1, K beta/K alpha, KLM/KLL, KMM/KLL, and the total K-shell fluorescence yields, omega(sub k), obtained in the present work have been compared with other theoretical data and solid-state measurements, finding good general agreement with the latter. The Kalpha 2/K alpha l ratio is found to be sensitive to the excitation mechanism. From these comparisons it has been possible to estimate an accuracy of approx.10% for the present transition probabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Icar..306..150P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Icar..306..150P"><span>Melting phase relations in the <span class="hlt">Fe</span>-S and <span class="hlt">Fe</span>-S-O systems at core conditions in small terrestrial bodies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pommier, Anne; Laurenz, Vera; Davies, Christopher J.; Frost, Daniel J.</p> <p>2018-05-01</p> <p>We report an experimental investigation of phase equilibria in the <span class="hlt">Fe</span>-S and <span class="hlt">Fe</span>-S-O systems. Experiments were performed at high temperatures (1400-1850 °C) and high pressures (14 and 20 GPa) using a multi-anvil apparatus. The results of this study are used to understand the effect of sulfur and oxygen on core dynamics in small terrestrial bodies. We observe that the formation of solid <span class="hlt">Fe</span>O grains occurs at the <span class="hlt">Fe</span>-S liquid - <span class="hlt">Fe</span> solid interface at high temperature ( > 1400 °C at 20 GPa). Oxygen fugacities calculated for each O-bearing sample show that redox conditions vary from ΔIW = -0.65 to 0. Considering the relative density of each phase and existing evolutionary <span class="hlt">models</span> of terrestrial cores, we apply our experimental results to the cores of Mars and Ganymede. We suggest that the presence of <span class="hlt">Fe</span>O in small terrestrial bodies tends to contribute to outer-core compositional stratification. Depending on the redox and thermal history of the planet, <span class="hlt">Fe</span>O may also help form a transitional redox zone at the core-mantle boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=113689&keyword=time+AND+series+AND+forecasting&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=113689&keyword=time+AND+series+AND+forecasting&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span><span class="hlt">MODELS</span> FOR SUBMARINE OUTFALL - <span class="hlt">VALIDATION</span> AND PREDICTION UNCERTAINTIES</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This address reports on some efforts to verify and <span class="hlt">validate</span> dilution <span class="hlt">models</span>, including those found in Visual Plumes. This is done in the context of problem experience: a range of problems, including different pollutants such as bacteria; scales, including near-field and far-field...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27292581','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27292581"><span>Development and <span class="hlt">validation</span> of a building design waste reduction <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Llatas, C; Osmani, M</p> <p>2016-10-01</p> <p>Reduction in construction waste is a pressing need in many countries. The design of building elements is considered a pivotal process to achieve waste reduction at source, which enables an informed prediction of their wastage reduction levels. However the lack of quantitative methods linking design strategies to waste reduction hinders designing out waste practice in building projects. Therefore, this paper addresses this knowledge gap through the design and <span class="hlt">validation</span> of a Building Design Waste Reduction Strategies (Waste ReSt) <span class="hlt">model</span> that aims to investigate the relationships between design variables and their impact on onsite waste reduction. The Waste ReSt <span class="hlt">model</span> was <span class="hlt">validated</span> in a real-world case study involving 20 residential buildings in Spain. The <span class="hlt">validation</span> process comprises three stages. Firstly, design waste causes were analyzed. Secondly, design strategies were applied leading to several alternative low waste building elements. Finally, their potential source reduction levels were quantified and discussed within the context of the literature. The Waste ReSt <span class="hlt">model</span> could serve as an instrumental tool to simulate designing out strategies in building projects. The knowledge provided by the <span class="hlt">model</span> could help project stakeholders to better understand the correlation between the design process and waste sources and subsequently implement design practices for low-waste buildings. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17425078','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17425078"><span>Sewer solids separation by sedimentation--the problem of <span class="hlt">modeling</span>, <span class="hlt">validation</span> and transferability.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kutzner, R; Brombach, H; Geiger, W F</p> <p>2007-01-01</p> <p>Sedimentation of sewer solids in tanks, ponds and similar devices is the most relevant process for the treatment of stormwater and combined sewer overflows in urban collecting systems. In the past a lot of research work was done to develop deterministic <span class="hlt">models</span> for the description of this separation process. But these modern <span class="hlt">models</span> are not commonly accepted in Germany until today. Water Authorities are sceptical with regard to <span class="hlt">model</span> <span class="hlt">validation</span> and transferability. Within this paper it is checked whether this scepticism is reasonable. A framework-proposal for the <span class="hlt">validation</span> of mathematical <span class="hlt">models</span> with zero or one dimensional spatial resolution for particle separation processes for stormwater and combined sewer overflow treatment is presented. This proposal was applied to publications of repute on sewer solids separation by sedimentation. The result was that none of the investigated <span class="hlt">models</span> described in literature passed the <span class="hlt">validation</span> entirely. There is an urgent need for future research in sewer solids sedimentation and remobilization!</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25111293','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25111293"><span>Parental <span class="hlt">modelling</span> of eating behaviours: observational <span class="hlt">validation</span> of the Parental <span class="hlt">Modelling</span> of Eating Behaviours scale (PARM).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Palfreyman, Zoe; Haycraft, Emma; Meyer, Caroline</p> <p>2015-03-01</p> <p>Parents are important role <span class="hlt">models</span> for their children's eating behaviours. This study aimed to further <span class="hlt">validate</span> the recently developed Parental <span class="hlt">Modelling</span> of Eating Behaviours Scale (PARM) by examining the relationships between maternal self-reports on the PARM with the <span class="hlt">modelling</span> practices exhibited by these mothers during three family mealtime observations. Relationships between observed maternal <span class="hlt">modelling</span> and maternal reports of children's eating behaviours were also explored. Seventeen mothers with children aged between 2 and 6 years were video recorded at home on three separate occasions whilst eating a meal with their child. Mothers also completed the PARM, the Children's Eating Behaviour Questionnaire and provided demographic information about themselves and their child. Findings provided <span class="hlt">validation</span> for all three PARM subscales, which were positively associated with their observed counterparts on the observational coding scheme (PARM-O). The results also indicate that habituation to observations did not change the feeding behaviours displayed by mothers. In addition, observed maternal <span class="hlt">modelling</span> was significantly related to children's food responsiveness (i.e., their interest in and desire for foods), enjoyment of food, and food fussiness. This study makes three important contributions to the literature. It provides construct <span class="hlt">validation</span> for the PARM measure and provides further observational support for maternal <span class="hlt">modelling</span> being related to lower levels of food fussiness and higher levels of food enjoyment in their children. These findings also suggest that maternal feeding behaviours remain consistent across repeated observations of family mealtimes, providing <span class="hlt">validation</span> for previous research which has used single observations. Copyright © 2014 Elsevier Ltd. All rights reserved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/34268','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/34268"><span>U.S. 75 Dallas, Texas, <span class="hlt">Model</span> <span class="hlt">Validation</span> and Calibration Report</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>2010-02-01</p> <p>This report presents the <span class="hlt">model</span> <span class="hlt">validation</span> and calibration results of the Integrated Corridor Management (ICM) analysis, <span class="hlt">modeling</span>, and simulation (AMS) for the U.S. 75 Corridor in Dallas, Texas. The purpose of the project was to estimate the benefits ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29051222','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29051222"><span>Development and <span class="hlt">Validation</span> of a Predictive <span class="hlt">Model</span> for Functional Outcome After Stroke Rehabilitation: The Maugeri <span class="hlt">Model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scrutinio, Domenico; Lanzillo, Bernardo; Guida, Pietro; Mastropasqua, Filippo; Monitillo, Vincenzo; Pusineri, Monica; Formica, Roberto; Russo, Giovanna; Guarnaschelli, Caterina; Ferretti, Chiara; Calabrese, Gianluigi</p> <p>2017-12-01</p> <p>Prediction of outcome after stroke rehabilitation may help clinicians in decision-making and planning rehabilitation care. We developed and <span class="hlt">validated</span> a predictive tool to estimate the probability of achieving improvement in physical functioning (<span class="hlt">model</span> 1) and a level of independence requiring no more than supervision (<span class="hlt">model</span> 2) after stroke rehabilitation. The <span class="hlt">models</span> were derived from 717 patients admitted for stroke rehabilitation. We used multivariable logistic regression analysis to build each <span class="hlt">model</span>. Then, each <span class="hlt">model</span> was prospectively <span class="hlt">validated</span> in 875 patients. <span class="hlt">Model</span> 1 included age, time from stroke occurrence to rehabilitation admission, admission motor and cognitive Functional Independence Measure scores, and neglect. <span class="hlt">Model</span> 2 included age, male gender, time since stroke onset, and admission motor and cognitive Functional Independence Measure score. Both <span class="hlt">models</span> demonstrated excellent discrimination. In the derivation cohort, the area under the curve was 0.883 (95% confidence intervals, 0.858-0.910) for <span class="hlt">model</span> 1 and 0.913 (95% confidence intervals, 0.884-0.942) for <span class="hlt">model</span> 2. The Hosmer-Lemeshow χ 2 was 4.12 ( P =0.249) and 1.20 ( P =0.754), respectively. In the <span class="hlt">validation</span> cohort, the area under the curve was 0.866 (95% confidence intervals, 0.840-0.892) for <span class="hlt">model</span> 1 and 0.850 (95% confidence intervals, 0.815-0.885) for <span class="hlt">model</span> 2. The Hosmer-Lemeshow χ 2 was 8.86 ( P =0.115) and 34.50 ( P =0.001), respectively. Both improvement in physical functioning (hazard ratios, 0.43; 0.25-0.71; P =0.001) and a level of independence requiring no more than supervision (hazard ratios, 0.32; 0.14-0.68; P =0.004) were independently associated with improved 4-year survival. A calculator is freely available for download at https://goo.gl/fEAp81. This study provides researchers and clinicians with an easy-to-use, accurate, and <span class="hlt">validated</span> predictive tool for potential application in rehabilitation research and stroke management. © 2017 American Heart Association, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27370204','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27370204"><span>Independent external <span class="hlt">validation</span> of predictive <span class="hlt">models</span> for urinary dysfunction following external beam radiotherapy of the prostate: Issues in <span class="hlt">model</span> development and reporting.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yahya, Noorazrul; Ebert, Martin A; Bulsara, Max; Kennedy, Angel; Joseph, David J; Denham, James W</p> <p>2016-08-01</p> <p>Most predictive <span class="hlt">models</span> are not sufficiently <span class="hlt">validated</span> for prospective use. We performed independent external <span class="hlt">validation</span> of published predictive <span class="hlt">models</span> for urinary dysfunctions following radiotherapy of the prostate. Multivariable <span class="hlt">models</span> developed to predict atomised and generalised urinary symptoms, both acute and late, were considered for <span class="hlt">validation</span> using a dataset representing 754 participants from the TROG 03.04-RADAR trial. Endpoints and features were harmonised to match the predictive <span class="hlt">models</span>. The overall performance, calibration and discrimination were assessed. 14 <span class="hlt">models</span> from four publications were <span class="hlt">validated</span>. The discrimination of the predictive <span class="hlt">models</span> in an independent external <span class="hlt">validation</span> cohort, measured using the area under the receiver operating characteristic (ROC) curve, ranged from 0.473 to 0.695, generally lower than in internal <span class="hlt">validation</span>. 4 <span class="hlt">models</span> had ROC >0.6. Shrinkage was required for all predictive <span class="hlt">models</span>' coefficients ranging from -0.309 (prediction probability was inverse to observed proportion) to 0.823. Predictive <span class="hlt">models</span> which include baseline symptoms as a feature produced the highest discrimination. Two <span class="hlt">models</span> produced a predicted probability of 0 and 1 for all patients. Predictive <span class="hlt">models</span> vary in performance and transferability illustrating the need for improvements in <span class="hlt">model</span> development and reporting. Several <span class="hlt">models</span> showed reasonable potential but efforts should be increased to improve performance. Baseline symptoms should always be considered as potential features for predictive <span class="hlt">models</span>. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915893K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915893K"><span>Ligand-controlled <span class="hlt">Fe</span> mobilization catalyzed by adsorbed <span class="hlt">Fe</span>(II) on <span class="hlt">Fe</span>(hydr)oxides</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kang, Kyounglim; Biswakarma, Jagannath; Borowski, Susan C.; Hug, Stephan J.; Hering, Janet G.; Schenkeveld, Walter D. C.; Kraemer, Stephan M.</p> <p>2017-04-01</p> <p>Dissolution of <span class="hlt">Fe</span>(hydr)oxides is a key process in biological iron acquisition. Due to the low solubility of iron oxides in environments with a circumneutral pH, organisms may exude organic compounds catalyzing iron mobilization by reductive and ligand controlled dissolution mechanisms. Recently, we have shown synergistic effects between reductive dissolution and ligand-controlled dissolution that may operate in biological iron acquisition. The synergistic effects were observed in <span class="hlt">Fe</span> mobilization from single goethite suspensions as well as in suspensions containing calcareous soil[1],[2]. However, how the redox reaction accelerates <span class="hlt">Fe</span>(hydr)oxide dissolution by ligands is not studied intensively. In our study, we hypothesized that electron transfer to structural <span class="hlt">Fe</span>(III) labilizes the <span class="hlt">Fe</span>(hydr)oxide structure, and that this can accelerate ligand controlled dissolution. Systematical batch dissolution experiments were carried out under anoxic conditions at environmentally relevant pH values in which various <span class="hlt">Fe</span>(hydr)oxides (goethite, hematite, lepidocrocite) interacted with two different types of ligand (desferrioxamine B (DFOB) and N,N'-Di(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid monohydrochloride (HBED)). Electron transfer to the structure was induced by adsorbing <span class="hlt">Fe</span>(II) to the mineral surface at various <span class="hlt">Fe</span>(II) concentrations. Our results show a distinct catalytic effect of adsorbed <span class="hlt">Fe</span>(II) on ligand controlled dissolution, even at submicromolar <span class="hlt">Fe</span>(II) concentrations. We observed the effect for a range of iron oxides, but it was strongest in lepidocrocite, most likely due to anisotropy in conductivity leading to higher near-surface concentration of reduced iron. Our results demonstrate that the catalytic effect of reductive processes on ligand controlled dissolution require a very low degree of reduction making this an efficient process for biological iron acquisition and a potentially important effect in natural iron cycling. References 1. Wang, Z. M</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=coefficient+AND+determination&pg=5&id=EJ827871','ERIC'); return false;" href="https://eric.ed.gov/?q=coefficient+AND+determination&pg=5&id=EJ827871"><span>Exact Analysis of Squared Cross-<span class="hlt">Validity</span> Coefficient in Predictive Regression <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Shieh, Gwowen</p> <p>2009-01-01</p> <p>In regression analysis, the notion of population <span class="hlt">validity</span> is of theoretical interest for describing the usefulness of the underlying regression <span class="hlt">model</span>, whereas the presumably more important concept of population cross-<span class="hlt">validity</span> represents the predictive effectiveness for the regression equation in future research. It appears that the inference…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19686024','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19686024"><span><span class="hlt">Modeling</span> the effects of argument length and <span class="hlt">validity</span> on inductive and deductive reasoning.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rotello, Caren M; Heit, Evan</p> <p>2009-09-01</p> <p>In an effort to assess <span class="hlt">models</span> of inductive reasoning and deductive reasoning, the authors, in 3 experiments, examined the effects of argument length and logical <span class="hlt">validity</span> on evaluation of arguments. In Experiments 1a and 1b, participants were given either induction or deduction instructions for a common set of stimuli. Two distinct effects were observed: Induction judgments were more affected by argument length, and deduction judgments were more affected by <span class="hlt">validity</span>. In Experiment 2, fluency was manipulated by displaying the materials in a low-contrast font, leading to increased sensitivity to logical <span class="hlt">validity</span>. Several variants of 1-process and 2-process <span class="hlt">models</span> of reasoning were assessed against the results. A 1-process <span class="hlt">model</span> that assumed the same scale of argument strength underlies induction and deduction was not successful. A 2-process <span class="hlt">model</span> that assumed separate, continuous informational dimensions of apparent deductive <span class="hlt">validity</span> and associative strength gave the more successful account. (c) 2009 APA, all rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApSS..428..748N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApSS..428..748N"><span>Spray deposited Mn<span class="hlt">Fe</span>2O4 thin films for detection of ethanol and acetone vapors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nagarajan, V.; Thayumanavan, A.</p> <p>2018-01-01</p> <p>Spinel Mn<span class="hlt">Fe</span>2O4 films were synthesized with the help of spray pyrolysis technique. The morphology study shows fine crushed sand grain morphology of the film. The structural investigation verifies the polycrystalline nature of prepared Mn<span class="hlt">Fe</span>2O4 films, which possess the spinel structure. Crystalline size is found to be around 23.5 nm-37.4 nm morphology analyses. Energy dispersive spectroscopy <span class="hlt">validates</span> the presence of oxygen, iron and manganese in Mn<span class="hlt">Fe</span>2O4 film. The prepared Mn<span class="hlt">Fe</span>2O4 film is extremely sensitive towards ethanol molecules at 300 K. The electrical resistance of Mn<span class="hlt">Fe</span>2O4 thin film decreases quickly when ethanol and acetone vapor molecules are adsorbed on base material. The synthesized Mn<span class="hlt">Fe</span>2O4 film is also highly sensitive towards acetone molecules at ambient temperature. The selectivity, sensing response, stability and recovery time of Mn<span class="hlt">Fe</span>2O4 film towards acetone and ethanol detection are analyzed in the present work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23040563','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23040563"><span>Transformation impacts of dissolved and solid phase <span class="hlt">Fe</span>(II) on trichloroethylene (TCE) reduction in an iron-reducing bacteria (IRB) mixed column system: a mathematical <span class="hlt">model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bae, Yeunook; Kim, Dooil; Cho, Hyun-Hee; Singhal, Naresh; Park, Jae-Woo</p> <p>2012-12-01</p> <p>In this research, we conducted trichloroethylene (TCE) reduction in a column filled with iron and iron-reducing bacteria (IRB) and developed a mathematical <span class="hlt">model</span> to investigate the critical reactions between active species in iron/IRB/contaminant systems. The formation of ferrous iron (<span class="hlt">Fe</span>(II)) in this system with IRB and zero-valent iron (ZVI, <span class="hlt">Fe</span>(0)) coated with a ferric iron (<span class="hlt">Fe</span>(III)) crust significantly affected TCE reduction and IRB respiration in various ways. This study presents a new framework for transformation property and reducing ability of both dissolved (<span class="hlt">Fe</span>(II)(dissolved)) and solid form ferrous iron (<span class="hlt">Fe</span>(II)(solid)). Results showed that TCE reduction was strongly depressed by <span class="hlt">Fe</span>(II)(solid) rather than by other inhibitors (e.g., <span class="hlt">Fe</span>(III) and lactate), suggesting that <span class="hlt">Fe</span>(II)(solid) might reduce IRB activation due to attachment to IRB cells. Newly exposed <span class="hlt">Fe</span>(0) from the released <span class="hlt">Fe</span>(II)(dissolved) was a strong contributor to TCE reduction compared to <span class="hlt">Fe</span>(II)(solid). In addition, our research confirmed that less <span class="hlt">Fe</span>(II)(solid) production strongly supported long-term TCE reduction because it may create an easier TCE approach to <span class="hlt">Fe</span>(0) or increase IRB growth. Our findings will aid the understanding of the contributions of iron media (e.g., <span class="hlt">Fe</span>(II)(solid), <span class="hlt">Fe</span>(II)(dissolved), <span class="hlt">Fe</span>(III), and <span class="hlt">Fe</span>(0)) to IRB for decontamination in natural groundwater systems. Copyright © 2012 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1323384','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1323384"><span>Electron transfer and atom exchange between aqueous <span class="hlt">Fe</span>(II) and structural <span class="hlt">Fe</span>(III) in clays. Role in U and Hg(II) transformations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Scherer, Michelle</p> <p>2016-08-31</p> <p>During this project, we investigated <span class="hlt">Fe</span> electron transfer and atom exchange between aqueous <span class="hlt">Fe</span>(II) and structural <span class="hlt">Fe</span>(III) in clay minerals. We used selective chemical extractions, enriched <span class="hlt">Fe</span> isotope tracer experiments, computational molecular <span class="hlt">modeling</span>, and Mössbauer spectroscopy. Our findings indicate that structural <span class="hlt">Fe</span>(III) in clay minerals is reduced by aqueous <span class="hlt">Fe</span>(II) and that electron transfer occurs when <span class="hlt">Fe</span>(II) is sorbed to either basal planes and edge OH-groups of clay mineral. Findings from highly enriched isotope experiments suggest that up to 30 % of the <span class="hlt">Fe</span> atoms in the structure of some clay minerals exhanges with aqueous <span class="hlt">Fe</span>(II). First principles calculations usingmore » a small polaron hopping approach suggest surprisingly fast electron mobility at room temperature in a nontronite clay mineral and are consistent with temperature dependent Mössbauer data Fast electron mobility suggests that electrons may be able to conduct through the mineral fast enough to enable exchange of <span class="hlt">Fe</span> between the aqueous phase and clay mineral structure. over the time periods we observed. Our findings suggest that <span class="hlt">Fe</span> in clay minerals is not as stable as previously thought.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26867124','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26867124"><span>Finite element <span class="hlt">modeling</span> of human brain response to football helmet impacts.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Darling, T; Muthuswamy, J; Rajan, S D</p> <p>2016-10-01</p> <p>The football helmet is used to help mitigate the occurrence of impact-related traumatic (TBI) and minor traumatic brain injuries (mTBI) in the game of American football. While the current helmet design methodology may be adequate for reducing linear acceleration of the head and minimizing TBI, it however has had less effect in minimizing mTBI. The objectives of this study are (a) to develop and <span class="hlt">validate</span> a coupled finite element (<span class="hlt">FE</span>) <span class="hlt">model</span> of a football helmet and the human body, and (b) to assess responses of different regions of the brain to two different impact conditions - frontal oblique and crown impact conditions. The <span class="hlt">FE</span> helmet <span class="hlt">model</span> was <span class="hlt">validated</span> using experimental results of drop tests. Subsequently, the integrated helmet-human body <span class="hlt">FE</span> <span class="hlt">model</span> was used to assess the responses of different regions of the brain to impact loads. Strain-rate, strain, and stress measures in the corpus callosum, midbrain, and brain stem were assessed. Results show that maximum strain-rates of 27 and 19 s(-1) are observed in the brain-stem and mid-brain, respectively. This could potentially lead to axonal injuries and neuronal cell death during crown impact conditions. The developed experimental-numerical framework can be used in the study of other helmet-related impact conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=244910','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=244910"><span><span class="hlt">Validating</span> soil phosphorus routines in the SWAT <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Phosphorus transfer from agricultural soils to surface waters is an important environmental issue. Commonly used <span class="hlt">models</span> like SWAT have not always been updated to reflect improved understanding of soil P transformations and transfer to runoff. Our objective was to <span class="hlt">validate</span> the ability of the P routin...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3384226','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3384226"><span>Criteria of <span class="hlt">validity</span> for animal <span class="hlt">models</span> of psychiatric disorders: focus on anxiety disorders and depression</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2011-01-01</p> <p>Animal <span class="hlt">models</span> of psychiatric disorders are usually discussed with regard to three criteria first elaborated by Willner; face, predictive and construct <span class="hlt">validity</span>. Here, we draw the history of these concepts and then try to redraw and refine these criteria, using the framework of the diathesis <span class="hlt">model</span> of depression that has been proposed by several authors. We thus propose a set of five major criteria (with sub-categories for some of them); homological <span class="hlt">validity</span> (including species <span class="hlt">validity</span> and strain <span class="hlt">validity</span>), pathogenic <span class="hlt">validity</span> (including ontopathogenic <span class="hlt">validity</span> and triggering <span class="hlt">validity</span>), mechanistic <span class="hlt">validity</span>, face <span class="hlt">validity</span> (including ethological and biomarker <span class="hlt">validity</span>) and predictive <span class="hlt">validity</span> (including induction and remission <span class="hlt">validity</span>). Homological <span class="hlt">validity</span> requires that an adequate species and strain be chosen: considering species <span class="hlt">validity</span>, primates will be considered to have a higher score than drosophila, and considering strains, a high stress reactivity in a strain scores higher than a low stress reactivity in another strain. Pathological <span class="hlt">validity</span> corresponds to the fact that, in order to shape pathological characteristics, the organism has been manipulated both during the developmental period (for example, maternal separation: ontopathogenic <span class="hlt">validity</span>) and during adulthood (for example, stress: triggering <span class="hlt">validity</span>). Mechanistic <span class="hlt">validity</span> corresponds to the fact that the cognitive (for example, cognitive bias) or biological mechanisms (such as dysfunction of the hormonal stress axis regulation) underlying the disorder are identical in both humans and animals. Face <span class="hlt">validity</span> corresponds to the observable behavioral (ethological <span class="hlt">validity</span>) or biological (biomarker <span class="hlt">validity</span>) outcomes: for example anhedonic behavior (ethological <span class="hlt">validity</span>) or elevated corticosterone (biomarker <span class="hlt">validity</span>). Finally, predictive <span class="hlt">validity</span> corresponds to the identity of the relationship between the triggering factor and the outcome (induction <span class="hlt">validity</span>) and between the effects of the treatments</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.4484T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.4484T"><span>Calibration and <span class="hlt">validation</span> of earthquake catastrophe <span class="hlt">models</span>. Case study: Impact Forecasting Earthquake <span class="hlt">Model</span> for Algeria</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trendafiloski, G.; Gaspa Rebull, O.; Ewing, C.; Podlaha, A.; Magee, B.</p> <p>2012-04-01</p> <p>Calibration and <span class="hlt">validation</span> are crucial steps in the production of the catastrophe <span class="hlt">models</span> for the insurance industry in order to assure the <span class="hlt">model</span>'s reliability and to quantify its uncertainty. Calibration is needed in all components of <span class="hlt">model</span> development including hazard and vulnerability. <span class="hlt">Validation</span> is required to ensure that the losses calculated by the <span class="hlt">model</span> match those observed in past events and which could happen in future. Impact Forecasting, the catastrophe <span class="hlt">modelling</span> development centre of excellence within Aon Benfield, has recently launched its earthquake <span class="hlt">model</span> for Algeria as a part of the earthquake <span class="hlt">model</span> for the Maghreb region. The earthquake <span class="hlt">model</span> went through a detailed calibration process including: (1) the seismic intensity attenuation <span class="hlt">model</span> by use of macroseismic observations and maps from past earthquakes in Algeria; (2) calculation of the country-specific vulnerability modifiers by use of past damage observations in the country. The use of Benouar, 1994 ground motion prediction relationship was proven as the most appropriate for our <span class="hlt">model</span>. Calculation of the regional vulnerability modifiers for the country led to 10% to 40% larger vulnerability indexes for different building types compared to average European indexes. The country specific damage <span class="hlt">models</span> also included aggregate damage <span class="hlt">models</span> for residential, commercial and industrial properties considering the description of the buildings stock given by World Housing Encyclopaedia and the local rebuilding cost factors equal to 10% for damage grade 1, 20% for damage grade 2, 35% for damage grade 3, 75% for damage grade 4 and 100% for damage grade 5. The damage grades comply with the European Macroseismic Scale (EMS-1998). The <span class="hlt">model</span> was <span class="hlt">validated</span> by use of "as-if" historical scenario simulations of three past earthquake events in Algeria M6.8 2003 Boumerdes, M7.3 1980 El-Asnam and M7.3 1856 Djidjelli earthquake. The calculated return periods of the losses for client market portfolio align with the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22370470-isochrones-old-gyr-stars-stellar-populations-models-fe-+0-fe-+0','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22370470-isochrones-old-gyr-stars-stellar-populations-models-fe-+0-fe-+0"><span>Isochrones for old (>5 Gyr) stars and stellar populations. I. <span class="hlt">Models</span> for –2.4 ≤ [<span class="hlt">Fe</span>/H] ≤+0.6, 0.25 ≤ Y ≤ 0.33, and –0.4 ≤ [α/<span class="hlt">Fe</span>] ≤+0.4</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>VandenBerg, Don A.; Bergbusch, Peter A.; Ferguson, Jason W.</p> <p>2014-10-10</p> <p>Canonical grids of stellar evolutionary sequences have been computed for the helium mass-fraction abundances Y = 0.25, 0.29, and 0.33, and for iron abundances that vary from –2.4 to +0.4 (in 0.2 dex increments) when [α/<span class="hlt">Fe</span>] =+0.4, or for the ranges –2.0 ≤ [<span class="hlt">Fe</span>/H] ≤+0.6, –1.8 ≤ [<span class="hlt">Fe</span>/H] ≤+0.6 when [α/<span class="hlt">Fe</span>] =0.0 and –0.4, respectively. The grids, which consist of tracks for masses from 0.12 M{sub ⊙} to 1.1-1.5 M{sub ⊙} (depending on the metallicity) are based on up-to-date physics, including the gravitational settling of helium (but not metals diffusion). Interpolation software is provided to generate isochrones for arbitrary agesmore » between ≈5 and 15 Gyr and any values of Y, [α/<span class="hlt">Fe</span>], and [<span class="hlt">Fe</span>/H] within the aformentioned ranges. Comparisons of isochrones with published color-magnitude diagrams (CMDs) for the open clusters M67 ([<span class="hlt">Fe</span>/H] ≈0.0) and NGC 6791 ([<span class="hlt">Fe</span>/H] ≈0.3) and for four of the metal-poor globular clusters (47 Tuc, M3, M5, and M92) indicate that the <span class="hlt">models</span> for the observed metallicities do a reasonably good job of reproducing the locations and slopes of the cluster main sequences and giant branches. The same conclusion is reached from a consideration of plots of nearby subdwarfs that have accurate Hipparcos parallaxes and metallicities in the range –2.0 ≲ [<span class="hlt">Fe</span>/H] ≲ –1.0 on various CMDs and on the (log T {sub eff}, M{sub V} ) diagram. A relatively hot temperature scale similar to that derived in recent calibrations of the infrared flux method is favored by both the isochrones and the adopted color transformations, which are based on the latest MARCS <span class="hlt">model</span> atmospheres.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPSJ...81h4701S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPSJ...81h4701S"><span>First-Principles Study on the Gilbert Damping Constants of Transition Metal Alloys, <span class="hlt">Fe</span>--Ni and <span class="hlt">Fe</span>--Pt Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sakuma, Akimasa</p> <p>2012-08-01</p> <p>We adapt the tight-binding linear muffin-tin orbital (TB-LMTO) method to the torque-correlation <span class="hlt">model</span> for the Gilbert damping constant α and perform the first-principles calculation for disordered transition metal alloys, <span class="hlt">Fe</span>--Ni and <span class="hlt">Fe</span>--Pt systems, within the framework of the CPA. Quantitatively, the calculated α values are about one-half of the experimental values, whereas the variations in the Fermi level dependence of α are much larger than these discrepancies. As expected, we confirm in the (<span class="hlt">Fe</span>--Ni)1-XPtX and <span class="hlt">Fe</span>Pt systems that Pt atoms certainly enhance α owing to their large spin--orbit coupling. For the disordered alloys, we find that α decreases with increasing chemical degree of order in a wide range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SuScT..23e4001T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SuScT..23e4001T"><span>Transport and superconducting properties of <span class="hlt">Fe</span>-based superconductors: a comparison between Sm<span class="hlt">Fe</span>AsO1-xFx and <span class="hlt">Fe</span>1+yTe1-xSex</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tropeano, M.; Pallecchi, I.; Cimberle, M. R.; Ferdeghini, C.; Lamura, G.; Vignolo, M.; Martinelli, A.; Palenzona, A.; Putti, M.</p> <p>2010-05-01</p> <p>In this paper we carry out a direct comparison between transport and superconducting properties—namely resistivity, magnetoresistivity, Hall effect, Seebeck effect, thermal conductivity, upper critical field—of two different families of <span class="hlt">Fe</span>-based superconductors, which can be viewed in many respects as end members: Sm<span class="hlt">Fe</span>AsO1 - xFx with the largest Tc and the largest anisotropy and <span class="hlt">Fe</span>1 + yTe1 - xSex, with the largest Hc2, the lowest Tc and the lowest anisotropy. In the case of the Sm<span class="hlt">Fe</span>AsO1 - xFx series, we find that a single-band description allows us to extract an approximate estimation of band parameters such as carrier density and mobility from experimental data, although the behaviour of the Seebeck effect as a function of doping demonstrates that a multiband description would be more appropriate. On the contrary, experimental data for the <span class="hlt">Fe</span>1 + y(Te1 - x, Sex) series exhibit a strongly compensated behaviour, which can be described only within a multiband <span class="hlt">model</span>. In the <span class="hlt">Fe</span>1 + y(Te1 - x, Sex) series, the role of the excess <span class="hlt">Fe</span>, tuned by Se stoichiometry, is found to be twofold: on one hand it dopes electrons in the system and on the other hand it introduces localized magnetic moments, responsible for Kondo like scattering and likely pairbreaking of Cooper pairs. Hence, <span class="hlt">Fe</span> excess also plays a crucial role in determining superconducting properties such as the Tc and the upper critical field Hc2. The huge Hc2 values of the <span class="hlt">Fe</span>1 + yTe1 - xSex samples are described by a dirty limit law, opposed to the clean limit behaviour of the Sm<span class="hlt">Fe</span>AsO1 - xFx samples. Hence, magnetic scattering by excess <span class="hlt">Fe</span> seems to drive the system in the dirty regime, but its detrimental pairbreaking role seems not to be as severe as predicted by theory. This issue has yet to be clarified, addressing the more fundamental issue of the interplay between magnetism and superconductivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150002331','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150002331"><span>Integrated Medical <span class="hlt">Model</span> Verification, <span class="hlt">Validation</span>, and Credibility</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Walton, Marlei; Kerstman, Eric; Foy, Millennia; Shah, Ronak; Saile, Lynn; Boley, Lynn; Butler, Doug; Myers, Jerry</p> <p>2014-01-01</p> <p>The Integrated Medical <span class="hlt">Model</span> (IMM) was designed to forecast relative changes for a specified set of crew health and mission success risk metrics by using a probabilistic (stochastic process) <span class="hlt">model</span> based on historical data, cohort data, and subject matter expert opinion. A probabilistic approach is taken since exact (deterministic) results would not appropriately reflect the uncertainty in the IMM inputs. Once the IMM was conceptualized, a plan was needed to rigorously assess input information, framework and code, and output results of the IMM, and ensure that end user requests and requirements were considered during all stages of <span class="hlt">model</span> development and implementation. METHODS: In 2008, the IMM team developed a comprehensive verification and <span class="hlt">validation</span> (VV) plan, which specified internal and external review criteria encompassing 1) verification of data and IMM structure to ensure proper implementation of the IMM, 2) several <span class="hlt">validation</span> techniques to confirm that the simulation capability of the IMM appropriately represents occurrences and consequences of medical conditions during space missions, and 3) credibility processes to develop user confidence in the information derived from the IMM. When the NASA-STD-7009 (7009) was published, the IMM team updated their verification, <span class="hlt">validation</span>, and credibility (VVC) project plan to meet 7009 requirements and include 7009 tools in reporting VVC status of the IMM. RESULTS: IMM VVC updates are compiled recurrently and include 7009 Compliance and Credibility matrices, IMM VV Plan status, and a synopsis of any changes or updates to the IMM during the reporting period. Reporting tools have evolved over the lifetime of the IMM project to better communicate VVC status. This has included refining original 7009 methodology with augmentation from the NASA-STD-7009 Guidance Document. End user requests and requirements are being satisfied as evidenced by ISS Program acceptance of IMM risk forecasts, transition to an operational <span class="hlt">model</span> and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OPhy...16...15Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OPhy...16...15Z"><span>Three phase heat and mass transfer <span class="hlt">model</span> for unsaturated soil freezing process: Part 2 - <span class="hlt">model</span> <span class="hlt">validation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Yaning; Xu, Fei; Li, Bingxi; Kim, Yong-Song; Zhao, Wenke; Xie, Gongnan; Fu, Zhongbin</p> <p>2018-04-01</p> <p>This study aims to <span class="hlt">validate</span> the three-phase heat and mass transfer <span class="hlt">model</span> developed in the first part (Three phase heat and mass transfer <span class="hlt">model</span> for unsaturated soil freezing process: Part 1 - <span class="hlt">model</span> development). Experimental results from studies and experiments were used for the <span class="hlt">validation</span>. The results showed that the correlation coefficients for the simulated and experimental water contents at different soil depths were between 0.83 and 0.92. The correlation coefficients for the simulated and experimental liquid water contents at different soil temperatures were between 0.95 and 0.99. With these high accuracies, the developed <span class="hlt">model</span> can be well used to predict the water contents at different soil depths and temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080006646','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080006646"><span>Flight Testing an Iced Business Jet for Flight Simulation <span class="hlt">Model</span> <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ratvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam; Cooper, Jon</p> <p>2007-01-01</p> <p>A flight test of a business jet aircraft with various ice accretions was performed to obtain data to <span class="hlt">validate</span> flight simulation <span class="hlt">models</span> developed through wind tunnel tests. Three types of ice accretions were tested: pre-activation roughness, runback shapes that form downstream of the thermal wing ice protection system, and a wing ice protection system failure shape. The high fidelity flight simulation <span class="hlt">models</span> of this business jet aircraft were <span class="hlt">validated</span> using a software tool called "Overdrive." Through comparisons of flight-extracted aerodynamic forces and moments to simulation-predicted forces and moments, the simulation <span class="hlt">models</span> were successfully <span class="hlt">validated</span>. Only minor adjustments in the simulation database were required to obtain adequate match, signifying the process used to develop the simulation <span class="hlt">models</span> was successful. The simulation <span class="hlt">models</span> were implemented in the NASA Ice Contamination Effects Flight Training Device (ICEFTD) to enable company pilots to evaluate flight characteristics of the simulation <span class="hlt">models</span>. By and large, the pilots confirmed good similarities in the flight characteristics when compared to the real airplane. However, pilots noted pitch up tendencies at stall with the flaps extended that were not representative of the airplane and identified some differences in pilot forces. The elevator hinge moment <span class="hlt">model</span> and implementation of the control forces on the ICEFTD were identified as a driver in the pitch ups and control force issues, and will be an area for future work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4983197','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4983197"><span>MolProbity’s Ultimate Rotamer-Library Distributions for <span class="hlt">Model</span> <span class="hlt">Validation</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hintze, Bradley J.; Lewis, Steven M.; Richardson, Jane S.; Richardson, David C.</p> <p>2016-01-01</p> <p>Here we describe the updated MolProbity rotamer-library distributions derived from an order-of-magnitude larger and more stringently quality-filtered dataset of about 8000 (vs. 500) protein chains, and we explain the resulting changes and improvements to <span class="hlt">model</span> <span class="hlt">validation</span> as seen by users. To include only sidechains with satisfactory justification for their given conformation, we added residue-specific filters for electron-density value and <span class="hlt">model</span>-to-density fit. The combined new protocol retains a million residues of data, while cleaning up false-positive noise in the multi-χ datapoint distributions. It enables unambiguous characterization of conformational clusters nearly 1000-fold less frequent than the most common ones. We describe examples of local interactions that favor these rare conformations, including the role of authentic covalent bond-angle deviations in enabling presumably strained sidechain conformations. Further, along with favored and outlier, an allowed category (0.3% to 2.0% occurrence in reference data) has been added, analogous to Ramachandran <span class="hlt">validation</span> categories. The new rotamer distributions are used for current rotamer <span class="hlt">validation</span> in Mol-Probity and PHENIX, and for rotamer choice in PHENIX <span class="hlt">model</span>-building and refinement. The multi-dimensional χ distributions and Top8000 reference dataset are freely available on GitHub. These rotamers are termed “ultimate” because data sampling and quality are now fully adequate for this task, and also because we believe the future of conformational <span class="hlt">validation</span> should integrate sidechain with backbone criteria. PMID:27018641</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1365689-data-driven-residential-load-modeling-validation-gridlab','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1365689-data-driven-residential-load-modeling-validation-gridlab"><span>Data-Driven Residential Load <span class="hlt">Modeling</span> and <span class="hlt">Validation</span> in GridLAB-D</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gotseff, Peter; Lundstrom, Blake</p> <p></p> <p>Accurately characterizing the impacts of high penetrations of distributed energy resources (DER) on the electric distribution system has driven <span class="hlt">modeling</span> methods from traditional static snap shots, often representing a critical point in time (e.g., summer peak load), to quasi-static time series (QSTS) simulations capturing all the effects of variable DER, associated controls and hence, impacts on the distribution system over a given time period. Unfortunately, the high time resolution DER source and load data required for <span class="hlt">model</span> inputs is often scarce or non-existent. This paper presents work performed within the GridLAB-D <span class="hlt">model</span> environment to synthesize, calibrate, and <span class="hlt">validate</span> 1-second residentialmore » load <span class="hlt">models</span> based on measured transformer loads and physics-based <span class="hlt">models</span> suitable for QSTS electric distribution system <span class="hlt">modeling</span>. The <span class="hlt">modeling</span> and <span class="hlt">validation</span> approach taken was to create a typical GridLAB-D <span class="hlt">model</span> home that, when replicated to represent multiple diverse houses on a single transformer, creates a statistically similar load to a measured load for a given weather input. The <span class="hlt">model</span> homes are constructed to represent the range of actual homes on an instrumented transformer: square footage, thermal integrity, heating and cooling system definition as well as realistic occupancy schedules. House <span class="hlt">model</span> calibration and <span class="hlt">validation</span> was performed using the distribution transformer load data and corresponding weather. The <span class="hlt">modeled</span> loads were found to be similar to the measured loads for four evaluation metrics: 1) daily average energy, 2) daily average and standard deviation of power, 3) power spectral density, and 4) load shape.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970017828','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970017828"><span>Turbulence <span class="hlt">Modeling</span> <span class="hlt">Validation</span>, Testing, and Development</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bardina, J. E.; Huang, P. G.; Coakley, T. J.</p> <p>1997-01-01</p> <p>The primary objective of this work is to provide accurate numerical solutions for selected flow fields and to compare and evaluate the performance of selected turbulence <span class="hlt">models</span> with experimental results. Four popular turbulence <span class="hlt">models</span> have been tested and <span class="hlt">validated</span> against experimental data often turbulent flows. The <span class="hlt">models</span> are: (1) the two-equation k-epsilon <span class="hlt">model</span> of Wilcox, (2) the two-equation k-epsilon <span class="hlt">model</span> of Launder and Sharma, (3) the two-equation k-omega/k-epsilon SST <span class="hlt">model</span> of Menter, and (4) the one-equation <span class="hlt">model</span> of Spalart and Allmaras. The flows investigated are five free shear flows consisting of a mixing layer, a round jet, a plane jet, a plane wake, and a compressible mixing layer; and five boundary layer flows consisting of an incompressible flat plate, a Mach 5 adiabatic flat plate, a separated boundary layer, an axisymmetric shock-wave/boundary layer interaction, and an RAE 2822 transonic airfoil. The experimental data for these flows are well established and have been extensively used in <span class="hlt">model</span> developments. The results are shown in the following four sections: Part A describes the equations of motion and boundary conditions; Part B describes the <span class="hlt">model</span> equations, constants, parameters, boundary conditions, and numerical implementation; and Parts C and D describe the experimental data and the performance of the <span class="hlt">models</span> in the free-shear flows and the boundary layer flows, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060051806','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060051806"><span>Pre-engineering Spaceflight <span class="hlt">Validation</span> of Environmental <span class="hlt">Models</span> and the 2005 HZETRN Simulation Code</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nealy, John E.; Cucinotta, Francis A.; Wilson, John W.; Badavi, Francis F.; Dachev, Ts. P.; Tomov, B. T.; Walker, Steven A.; DeAngelis, Giovanni; Blattnig, Steve R.; Atwell, William</p> <p>2006-01-01</p> <p>The HZETRN code has been identified by NASA for engineering design in the next phase of space exploration highlighting a return to the Moon in preparation for a Mars mission. In response, a new series of algorithms beginning with 2005 HZETRN, will be issued by correcting some prior limitations and improving control of propagated errors along with established code verification processes. Code <span class="hlt">validation</span> processes will use new/improved low Earth orbit (LEO) environmental <span class="hlt">models</span> with a recently improved International Space Station (ISS) shield <span class="hlt">model</span> to <span class="hlt">validate</span> computational <span class="hlt">models</span> and procedures using measured data aboard ISS. These <span class="hlt">validated</span> <span class="hlt">models</span> will provide a basis for flight-testing the designs of future space vehicles and systems of the Constellation program in the LEO environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013MMTB...44..506C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013MMTB...44..506C"><span>Viscosity Measurements of "<span class="hlt">Fe</span>O"-SiO2 Slag in Equilibrium with Metallic <span class="hlt">Fe</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Mao; Raghunath, Sreekanth; Zhao, Baojun</p> <p>2013-06-01</p> <p>The current study delivered the measurements of viscosities in the system "<span class="hlt">Fe</span>O"-SiO2 in equilibrium with metallic <span class="hlt">Fe</span> in the composition range between 15 and 40 wt pct SiO2. The experiments were carried out in the temperature range of 1473 K to 1773 K (1200 °C to 1500 °C) using a rotational spindle technique. An analysis of the quenched sample by electron probe X-ray microanalysis (EPMA) after the viscosity measurement enables the composition and microstructure of the slag to be directly linked with the viscosity. The current results are compared with available literature data. The significant discrepancies of the viscosity measurements in this system have been clarified. The possible reasons affecting the accuracy of the viscosity measurement have been discussed. The activation energies derived from the experimental data have a sharp increase at about 33 wt pct SiO2, which corresponds to the composition of fayalite (<span class="hlt">Fe</span>2SiO4). The modified quasi-chemical <span class="hlt">model</span> was constructed in the system "<span class="hlt">Fe</span>O"-SiO2 to describe the current viscosity data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23971910','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23971910"><span>Criterion for evaluating the predictive ability of nonlinear regression <span class="hlt">models</span> without cross-<span class="hlt">validation</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaneko, Hiromasa; Funatsu, Kimito</p> <p>2013-09-23</p> <p>We propose predictive performance criteria for nonlinear regression <span class="hlt">models</span> without cross-<span class="hlt">validation</span>. The proposed criteria are the determination coefficient and the root-mean-square error for the midpoints between k-nearest-neighbor data points. These criteria can be used to evaluate predictive ability after the regression <span class="hlt">models</span> are updated, whereas cross-<span class="hlt">validation</span> cannot be performed in such a situation. The proposed method is effective and helpful in handling big data when cross-<span class="hlt">validation</span> cannot be applied. By analyzing data from numerical simulations and quantitative structural relationships, we confirm that the proposed criteria enable the predictive ability of the nonlinear regression <span class="hlt">models</span> to be appropriately quantified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvC..94f5807L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvC..94f5807L"><span>β -decay rate of 59<span class="hlt">Fe</span> in shell burning environment and its influence on the production of 60<span class="hlt">Fe</span> in a massive star</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, K. A.; Lam, Y. H.; Qi, C.; Tang, X. D.; Zhang, N. T.</p> <p>2016-12-01</p> <p>We deduced the stellar β -decay rate of 59<span class="hlt">Fe</span> at typical carbon-shell burning temperature by taking the experimental Gamow-Teller transition strengths of the 59<span class="hlt">Fe</span> excited states. The result is also compared with those derived from large-scale shell <span class="hlt">model</span> calculations. The new rate is up to a factor of 2.5 lower than the theoretical rate of Fuller, Fowler, and Newman (FFN) and up to a factor of 5 higher than decay rate of Langanke and Martínez-Pinedo (LMP) in the temperature region 0.5 ≤T ≤2 GK. We estimated the impact of the newly determined rate on the synthesis of cosmic γ emitter 60<span class="hlt">Fe</span> in C-shell burning and explosive C/Ne burning using a one-zone <span class="hlt">model</span> calculation. Our results show that 59<span class="hlt">Fe</span> stellar β decay plays an important role in 60<span class="hlt">Fe</span> nucleosynthesis, even though the uncertainty of the decay rate is rather large due to the error of B (GT) strengths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JMEP...20..894L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JMEP...20..894L"><span><span class="hlt">Modeling</span> and <span class="hlt">FE</span> Simulation of Quenchable High Strength Steels Sheet Metal Hot Forming Process</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Hongsheng; Bao, Jun; Xing, Zhongwen; Zhang, Dejin; Song, Baoyu; Lei, Chengxi</p> <p>2011-08-01</p> <p>High strength steel (HSS) sheet metal hot forming process is investigated by means of numerical simulations. With regard to a reliable numerical process design, the knowledge of the thermal and thermo-mechanical properties is essential. In this article, tensile tests are performed to examine the flow stress of the material HSS 22MnB5 at different strains, strain rates, and temperatures. Constitutive <span class="hlt">model</span> based on phenomenological approach is developed to describe the thermo-mechanical properties of the material 22MnB5 by fitting the experimental data. A 2D coupled thermo-mechanical finite element (<span class="hlt">FE</span>) <span class="hlt">model</span> is developed to simulate the HSS sheet metal hot forming process for U-channel part. The ABAQUS/explicit <span class="hlt">model</span> is used conduct the hot forming stage simulations, and ABAQUS/implicit <span class="hlt">model</span> is used for accurately predicting the springback which happens at the end of hot forming stage. Material <span class="hlt">modeling</span> and <span class="hlt">FE</span> numerical simulations are carried out to investigate the effect of the processing parameters on the hot forming process. The processing parameters have significant influence on the microstructure of U-channel part. The springback after hot forming stage is the main factor impairing the shape precision of hot-formed part. The mechanism of springback is advanced and verified through numerical simulations and tensile loading-unloading tests. Creep strain is found in the tensile loading-unloading test under isothermal condition and has a distinct effect on springback. According to the numerical and experimental results, it can be concluded that springback is mainly caused by different cooling rats and the nonhomogengeous shrink of material during hot forming process, the creep strain is the main factor influencing the amount of the springback.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.B42C..01R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.B42C..01R"><span>Thermodynamic Versus Surface Area Control of Microbial <span class="hlt">Fe</span>(III) Oxide Reduction Kinetics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roden, E. E.</p> <p>2003-12-01</p> <p>Recent experimental studies of synthetic and natural <span class="hlt">Fe</span>(III) oxide reduction permit development of conceptual and quantitative <span class="hlt">models</span> of enzymatic <span class="hlt">Fe</span>(III) oxide reduction at circumneutral pH that can be compared to and contrasted with established <span class="hlt">models</span> of abiotic mineral dissolution. The findings collectively support a <span class="hlt">model</span> for controls on enzymatic reduction that differs fundamentally from those applied to abiotic reductive dissolution as a result of two basic phenomena: (1) the relatively minor influence of oxide mineralogical and thermodynamic properties on surface area-normalized rates of enzymatic reduction compared to abiotic reductive dissolution; and (2) the major limitation which sorption and/or surface precipitation of biogenic <span class="hlt">Fe</span>(II) on residual oxide and <span class="hlt">Fe</span>(III)-reducing bacterial cell surfaces poses to enzymatic electron transfer in the presence of excess electron donor. Parallel studies with two major <span class="hlt">Fe</span>(III)-reducing bacteria genera (Shewanella and Geobacter) lead to common conclusions regarding the importance of these phenomena in regulating the rate and long-term extent of <span class="hlt">Fe</span>(III) oxide reduction. Although the extent to which these phenomena can be traced to underlying kinetic vs. thermodynamic effects cannot be resolved with current information, <span class="hlt">models</span> in which rates of enzymatic reduction are limited kinetically by the abundance of "available" oxide surface sites (as controlled by oxide surface area and the abundance of surface-bound <span class="hlt">Fe</span>(II)) provide an adequate macroscopic description of controls on the initial rate and long-term extent of oxide reduction. In some instances, thermodynamic limitation posed by the accumulation of aqueous reaction end-products (i.e. <span class="hlt">Fe</span>(II) and alkalinity) must also be invoked to explain observed long-term patterns of reduction. In addition, the abundance of <span class="hlt">Fe</span>(III)-reducing microorganisms plays an important role in governing rates of reduction and needs to be considered in <span class="hlt">models</span> of <span class="hlt">Fe</span>(III) reduction in nonsteady</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.C53C0799H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.C53C0799H"><span><span class="hlt">Validation</span> of <span class="hlt">Modelled</span> Ice Dynamics of the Greenland Ice Sheet using Historical Forcing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoffman, M. J.; Price, S. F.; Howat, I. M.; Bonin, J. A.; Chambers, D. P.; Tezaur, I.; Kennedy, J. H.; Lenaerts, J.; Lipscomb, W. H.; Neumann, T.; Nowicki, S.; Perego, M.; Saba, J. L.; Salinger, A.; Guerber, J. R.</p> <p>2015-12-01</p> <p>Although ice sheet <span class="hlt">models</span> are used for sea level rise projections, the degree to which these <span class="hlt">models</span> have been <span class="hlt">validated</span> by observations is fairly limited, due in part to the limited duration of the satellite observation era and the long adjustment time scales of ice sheets. Here we describe a <span class="hlt">validation</span> framework for the Greenland Ice Sheet applied to the Community Ice Sheet <span class="hlt">Model</span> by forcing the <span class="hlt">model</span> annually with flux anomalies at the major outlet glaciers (Enderlin et al., 2014, observed from Landsat/ASTER/Operation IceBridge) and surface mass balance (van Angelen et al., 2013, calculated from RACMO2) for the period 1991-2012. The ice sheet <span class="hlt">model</span> output is compared to ice surface elevation observations from ICESat and ice sheet mass change observations from GRACE. Early results show promise for assessing the performance of different <span class="hlt">model</span> configurations. Additionally, we explore the effect of ice sheet <span class="hlt">model</span> resolution on <span class="hlt">validation</span> skill.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JMMM..439...17L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMMM..439...17L"><span>Effect of a Co<span class="hlt">Fe</span>B layer on the anisotropic magnetoresistance of Ta/Co<span class="hlt">FeB/MgO/NiFe/MgO/CoFe</span>B/Ta films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Minghua; Shi, Hui; Dong, Yuegang; Ding, Lei; Han, Gang; Zhang, Yao; Liu, Ye; Yu, Guanghua</p> <p>2017-10-01</p> <p>The anisotropic magnetoresistance (AMR) and magnetic properties of Ni<span class="hlt">Fe</span> films can be remarkably enhanced via Co<span class="hlt">Fe</span>B layer. In the case of an ultrathin Ni<span class="hlt">Fe</span> film having a Ta/Co<span class="hlt">FeB/MgO/NiFe/MgO/CoFe</span>B/Ta structure, the Co<span class="hlt">Fe</span>B/MgO layers suppressed the formation of magnetic dead layers and the interdiffusions and interface reactions between the Ni<span class="hlt">Fe</span> and Ta layers. The AMR reached a maximum value of 3.56% at 450 °C. More importantly, a single Ni<span class="hlt">Fe</span> (1 1 1) peak can be formed resulting in higher AMR values for films having Co<span class="hlt">Fe</span>B layer. This enhanced AMR also originated from the significant specular reflection of electrons owing to the crystalline MgO layer, together with the sharp interfaces with the Ni<span class="hlt">Fe</span> layer. These factors together resulted in higher AMR and improved magnetic properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29543944','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29543944"><span><span class="hlt">Validation</span> of the Colorado Retinopathy of Prematurity Screening <span class="hlt">Model</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McCourt, Emily A; Ying, Gui-Shuang; Lynch, Anne M; Palestine, Alan G; Wagner, Brandie D; Wymore, Erica; Tomlinson, Lauren A; Binenbaum, Gil</p> <p>2018-04-01</p> <p>The Colorado Retinopathy of Prematurity (CO-ROP) <span class="hlt">model</span> uses birth weight, gestational age, and weight gain at the first month of life (WG-28) to predict risk of severe retinopathy of prematurity (ROP). In previous <span class="hlt">validation</span> studies, the <span class="hlt">model</span> performed very well, predicting virtually all cases of severe ROP and potentially reducing the number of infants who need ROP examinations, warranting <span class="hlt">validation</span> in a larger, more diverse population. To <span class="hlt">validate</span> the performance of the CO-ROP <span class="hlt">model</span> in a large multicenter cohort. This study is a secondary analysis of data from the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study, a retrospective multicenter cohort study conducted in 29 hospitals in the United States and Canada between January 2006 and June 2012 of 6351 premature infants who received ROP examinations. Sensitivity and specificity for severe (early treatment of ROP [ETROP] type 1 or 2) ROP, and reduction in infants receiving examinations. The CO-ROP <span class="hlt">model</span> was applied to the infants in the G-ROP data set with all 3 data points (infants would have received examinations if they met all 3 criteria: birth weight, <1501 g; gestational age, <30 weeks; and WG-28, <650 g). Infants missing WG-28 information were included in a secondary analysis in which WG-28 was considered fewer than 650 g. Of 7438 infants in the G-ROP study, 3575 (48.1%) were girls, and maternal race/ethnicity was 2310 (31.1%) African American, 3615 (48.6%) white, 233 (3.1%) Asian, 40 (0.52%) American Indian/Alaskan Native, and 93 (1.3%) Pacific Islander. In the study cohort, 747 infants (11.8%) had type 1 or 2 ROP, 2068 (32.6%) had lower-grade ROP, and 3536 (55.6%) had no ROP. The CO-ROP <span class="hlt">model</span> had a sensitivity of 96.9% (95% CI, 95.4%-97.9%) and a specificity of 40.9% (95% CI, 39.3%-42.5%). It missed 23 (3.1%) infants who developed severe ROP. The CO-ROP <span class="hlt">model</span> would have reduced the number of infants who received examinations by 26.1% (95% CI, 25.0%-27.2%). The CO-ROP <span class="hlt">model</span> demonstrated high</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28091753','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28091753"><span>VTST/MT studies of the catalytic mechanism of C-H activation by transition metal complexes with [Cu2(μ-O2)], [<span class="hlt">Fe</span>2(μ-O2)] and <span class="hlt">Fe</span>(IV)-O cores based on DFT potential energy surfaces.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Yongho; Mai, Binh Khanh; Park, Sumin</p> <p>2017-04-01</p> <p>High-valent Cu and <span class="hlt">Fe</span> species, which are generated from dioxygen activation in metalloenzymes, carry out the functionalization of strong C-H bonds. Understanding the atomic details of the catalytic mechanism has long been one of the main objectives of bioinorganic chemistry. Large H/D kinetic isotope effects (KIEs) were observed in the C-H activation by high-valent non-heme Cu or <span class="hlt">Fe</span> complexes in enzymes and their synthetic <span class="hlt">models</span>. The H/D KIE depends significantly on the transition state properties, such as structure, energies, frequencies, and shape of the potential energy surface, when the tunneling effect is large. Therefore, theoretical predictions of kinetic parameters such as rate constants and KIEs can provide a reliable link between atomic-level quantum mechanical mechanisms and experiments. The accurate prediction of the tunneling effect is essential to reproduce the kinetic parameters. The rate constants and HD/KIE have been calculated using the variational transition-state theory including multidimensional tunneling based on DFT potential energy surfaces along the reaction coordinate. Excellent agreement was observed between the predicted and experimental results, which assures the <span class="hlt">validity</span> of the DFT potential energy surfaces and, therefore, the proposed atomic-level mechanisms. The [Cu 2 (μ-O) 2 ], [<span class="hlt">Fe</span> 2 (μ-O) 2 ], and <span class="hlt">Fe</span>(IV)-oxo species were employed for C-H activation, and their role as catalysts was discussed at an atomic level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4569327','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4569327"><span>Beyond Corroboration: Strengthening <span class="hlt">Model</span> <span class="hlt">Validation</span> by Looking for Unexpected Patterns</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chérel, Guillaume; Cottineau, Clémentine; Reuillon, Romain</p> <p>2015-01-01</p> <p><span class="hlt">Models</span> of emergent phenomena are designed to provide an explanation to global-scale phenomena from local-scale processes. <span class="hlt">Model</span> <span class="hlt">validation</span> is commonly done by verifying that the <span class="hlt">model</span> is able to reproduce the patterns to be explained. We argue that robust <span class="hlt">validation</span> must not only be based on corroboration, but also on attempting to falsify the <span class="hlt">model</span>, i.e. making sure that the <span class="hlt">model</span> behaves soundly for any reasonable input and parameter values. We propose an open-ended evolutionary method based on Novelty Search to look for the diverse patterns a <span class="hlt">model</span> can produce. The Pattern Space Exploration method was tested on a <span class="hlt">model</span> of collective motion and compared to three common a priori sampling experiment designs. The method successfully discovered all known qualitatively different kinds of collective motion, and performed much better than the a priori sampling methods. The method was then applied to a case study of city system dynamics to explore the model’s predicted values of city hierarchisation and population growth. This case study showed that the method can provide insights on potential predictive scenarios as well as falsifiers of the <span class="hlt">model</span> when the simulated dynamics are highly unrealistic. PMID:26368917</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170009816','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170009816"><span><span class="hlt">Validation</span> of Fatigue <span class="hlt">Modeling</span> Predictions in Aviation Operations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gregory, Kevin; Martinez, Siera; Flynn-Evans, Erin</p> <p>2017-01-01</p> <p>Bio-mathematical fatigue <span class="hlt">models</span> that predict levels of alertness and performance are one potential tool for use within integrated fatigue risk management approaches. A number of <span class="hlt">models</span> have been developed that provide predictions based on acute and chronic sleep loss, circadian desynchronization, and sleep inertia. Some are publicly available and gaining traction in settings such as commercial aviation as a means of evaluating flight crew schedules for potential fatigue-related risks. Yet, most <span class="hlt">models</span> have not been rigorously evaluated and independently <span class="hlt">validated</span> for the operations to which they are being applied and many users are not fully aware of the limitations in which <span class="hlt">model</span> results should be interpreted and applied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3683099','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3683099"><span>Mathematical <span class="hlt">model</span> of zinc absorption: effects of dietary calcium, protein and iron on zinc absorption</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Miller, Leland V.; Krebs, Nancy F.; Hambidge, K. Michael</p> <p>2013-01-01</p> <p>A previously described mathematical <span class="hlt">model</span> of Zn absorption as a function of total daily dietary Zn and phytate was fitted to data from studies in which dietary Ca, <span class="hlt">Fe</span> and protein were also measured. An analysis of regression residuals indicated statistically significant positive relationships between the residuals and Ca, <span class="hlt">Fe</span> and protein, suggesting that the presence of any of these dietary components enhances Zn absorption. Based on the hypotheses that (1) Ca and <span class="hlt">Fe</span> both promote Zn absorption by binding with phytate and thereby making it unavailable for binding Zn and (2) protein enhances the availability of Zn for transporter binding, the <span class="hlt">model</span> was modified to incorporate these effects. The new <span class="hlt">model</span> of Zn absorption as a function of dietary Zn, phytate, Ca, <span class="hlt">Fe</span> and protein was then fitted to the data. The proportion of variation in absorbed Zn explained by the new <span class="hlt">model</span> was 0·88, an increase from 0·82 with the original <span class="hlt">model</span>. A reduced version of the <span class="hlt">model</span> without <span class="hlt">Fe</span> produced an equally good fit to the data and an improved value for the <span class="hlt">model</span> selection criterion, demonstrating that when dietary Ca and protein are controlled for, there is no evidence that dietary <span class="hlt">Fe</span> influences Zn absorption. Regression residuals and testing with additional data supported the <span class="hlt">validity</span> of the new <span class="hlt">model</span>. It was concluded that dietary Ca and protein modestly enhanced Zn absorption and <span class="hlt">Fe</span> had no statistically discernable effect. Furthermore, the <span class="hlt">model</span> provides a meaningful foundation for efforts to <span class="hlt">model</span> nutrient interactions in mineral absorption. PMID:22617116</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22617116','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22617116"><span>Mathematical <span class="hlt">model</span> of zinc absorption: effects of dietary calcium, protein and iron on zinc absorption.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miller, Leland V; Krebs, Nancy F; Hambidge, K Michael</p> <p>2013-02-28</p> <p>A previously described mathematical <span class="hlt">model</span> of Zn absorption as a function of total daily dietary Zn and phytate was fitted to data from studies in which dietary Ca, <span class="hlt">Fe</span> and protein were also measured. An analysis of regression residuals indicated statistically significant positive relationships between the residuals and Ca, <span class="hlt">Fe</span> and protein, suggesting that the presence of any of these dietary components enhances Zn absorption. Based on the hypotheses that (1) Ca and <span class="hlt">Fe</span> both promote Zn absorption by binding with phytate and thereby making it unavailable for binding Zn and (2) protein enhances the availability of Zn for transporter binding, the <span class="hlt">model</span> was modified to incorporate these effects. The new <span class="hlt">model</span> of Zn absorption as a function of dietary Zn, phytate, Ca, <span class="hlt">Fe</span> and protein was then fitted to the data. The proportion of variation in absorbed Zn explained by the new <span class="hlt">model</span> was 0·88, an increase from 0·82 with the original <span class="hlt">model</span>. A reduced version of the <span class="hlt">model</span> without <span class="hlt">Fe</span> produced an equally good fit to the data and an improved value for the <span class="hlt">model</span> selection criterion, demonstrating that when dietary Ca and protein are controlled for, there is no evidence that dietary <span class="hlt">Fe</span> influences Zn absorption. Regression residuals and testing with additional data supported the <span class="hlt">validity</span> of the new <span class="hlt">model</span>. It was concluded that dietary Ca and protein modestly enhanced Zn absorption and <span class="hlt">Fe</span> had no statistically discernable effect. Furthermore, the <span class="hlt">model</span> provides a meaningful foundation for efforts to <span class="hlt">model</span> nutrient interactions in mineral absorption.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MSSP..100..940W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MSSP..100..940W"><span><span class="hlt">Model</span> updating strategy for structures with localised nonlinearities using frequency response measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Xing; Hill, Thomas L.; Neild, Simon A.; Shaw, Alexander D.; Haddad Khodaparast, Hamed; Friswell, Michael I.</p> <p>2018-02-01</p> <p>This paper proposes a <span class="hlt">model</span> updating strategy for localised nonlinear structures. It utilises an initial finite-element (<span class="hlt">FE</span>) <span class="hlt">model</span> of the structure and primary harmonic response data taken from low and high amplitude excitations. The underlying linear part of the <span class="hlt">FE</span> <span class="hlt">model</span> is first updated using low-amplitude test data with established techniques. Then, using this linear <span class="hlt">FE</span> <span class="hlt">model</span>, the nonlinear elements are localised, characterised, and quantified with primary harmonic response data measured under stepped-sine or swept-sine excitations. Finally, the resulting <span class="hlt">model</span> is <span class="hlt">validated</span> by comparing the analytical predictions with both the measured responses used in the updating and with additional test data. The proposed strategy is applied to a clamped beam with a nonlinear mechanism and good agreements between the analytical predictions and measured responses are achieved. Discussions on issues of damping estimation and dealing with data from amplitude-varying force input in the updating process are also provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23039071','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23039071"><span>Key hydride vibrational modes in [Ni<span class="hlt">Fe</span>] hydrogenase <span class="hlt">model</span> compounds studied by resonance Raman spectroscopy and density functional calculations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shafaat, Hannah S; Weber, Katharina; Petrenko, Taras; Neese, Frank; Lubitz, Wolfgang</p> <p>2012-11-05</p> <p>Hydrogenase proteins catalyze the reversible conversion of molecular hydrogen to protons and electrons. While many enzymatic states of the [Ni<span class="hlt">Fe</span>] hydrogenase have been studied extensively, there are multiple catalytically relevant EPR-silent states that remain poorly characterized. Analysis of <span class="hlt">model</span> compounds using new spectroscopic techniques can provide a framework for the study of these elusive states within the protein. We obtained optical absorption and resonance Raman (RR) spectra of (dppe)Ni(μ-pdt)<span class="hlt">Fe</span>(CO)(3) and [(dppe)Ni(μ-pdt)(μ-H)<span class="hlt">Fe</span>(CO)(3)][BF(4)], which are structural and functional <span class="hlt">model</span> compounds for the EPR-silent Ni-SI and Ni-R states of the [Ni<span class="hlt">Fe</span>] hydrogenase active site. The studies presented here use RR spectroscopy to probe vibrational modes of the active site, including metal-hydride stretching vibrations along with bridging ligand-metal and <span class="hlt">Fe</span>-CO bending vibrations, with isotopic substitution used to identify key metal-hydride modes. The metal-hydride vibrations are essentially uncoupled and represent isolated, localized stretching modes; the iron-hydride vibration occurs at 1530 cm(-1), while the nickel-hydride vibration is observed at 945 cm(-1). The significant discrepancy between the metal-hydride vibrational frequencies reflects the slight asymmetry in the metal-hydride bond lengths. Additionally, time-dependent density functional theory (TD-DFT) calculations were carried out to obtain theoretical RR spectra of these compounds. On the basis of the detailed comparison of theory and experiment, the dominant electronic transitions and significant normal modes probed in the RR experiments were assigned; the primary transitions in the visible wavelengths represent metal-to-metal and metal-to-ligand charge transfer bands. Inherent properties of metal-hydride vibrational modes in resonance Raman spectra and DFT calculations are discussed together with the prospects of observing such vibrational modes in metal-hydride-containing proteins. Such a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22004059-stellar-laboratory-xuv-euv-line-ratios-fe-xviii-fe-xix','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22004059-stellar-laboratory-xuv-euv-line-ratios-fe-xviii-fe-xix"><span>Stellar and laboratory XUV/EUV line ratios in <span class="hlt">Fe</span> XVIII and <span class="hlt">Fe</span> XIX</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Traebert, E.; Beiersdorfer, P.; Clementson, J.</p> <p>2012-05-25</p> <p>A so-called XUV excess has been suspected with the relative fluxes of <span class="hlt">Fe</span> XVIII and <span class="hlt">Fe</span> XIX lines observed in the XUV and EUV ranges of the spectrum of the star Capella as observed by the Chandra spacecraft, even after correction for interstellar absorption. This excess becomes apparent in the comparison of the observations with simulations of stellar spectra obtained using collisional-radiative <span class="hlt">models</span> that employ, for example, the Atomic Plasma Emission Code (APEC) or the Flexible Atomic Code (FAC). We have addressed this problem by laboratory studies using the Livermore electron beam ion trap (EBIT).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1253237','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1253237"><span>Evaluation on the Effect of Composition on Radiation Hardening and Embrittlement in <span class="hlt">Model</span> <span class="hlt">Fe</span>CrAl Alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Field, Kevin G.; Briggs, Samuel A.; Edmondson, Philip</p> <p>2015-09-18</p> <p>This report details the findings of post-radiation mechanical testing and microstructural characterization performed on a series of <span class="hlt">model</span> and commercial <span class="hlt">Fe</span>CrAl alloys to assist with the development of a cladding technology with enhanced accident tolerance. The samples investigated include <span class="hlt">model</span> alloys with simple ferritic grain structure and two commercial alloys with minor solute additions. These samples were irradiated in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) up to nominal doses of 7.0 dpa near or at Light Water Reactor (LWR) relevant temperatures (300-400 C). Characterization included a suite of techniques including small angle neutron scatteringmore » (SANS), atom probe tomography (APT), and transmission based electron microscopy techniques. Mechanical testing included tensile tests at room temperature on sub-sized tensile specimens. The goal of this work was to conduct detailed characterization and mechanical testing to begin establishing empirical and/or theoretical structure-property relationships for radiation-induced hardening and embrittlement in the <span class="hlt">Fe</span>CrAl alloy class. Development of such relationships will provide insight on the performance of <span class="hlt">Fe</span>CrAl alloys in an irradiation environment and will enable further development of the alloy class for applications within a LWR environment. A particular focus was made on establishing trends, including composition and radiation dose. The report highlights in detail the pertinent findings based on this work. This report shows that radiation hardening in the alloys is primarily composition dependent due to the phase separation in the high-Cr <span class="hlt">Fe</span>CrAl alloys. Other radiation induced/enhanced microstructural features were less dependent on composition and when observed at low number densities, were not a significant contributor to the observed mechanical responses. Pre-existing microstructure in the alloys was found to be important, with grain boundaries and pre</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. Their policies may differ from this site.</div> </div><!-- container --> <footer><a id="backToTop" href="#top"> </a><nav><a id="backToTop" href="#top"> </a><ul class="links"><a id="backToTop" href="#top"> </a><li><a id="backToTop" href="#top"></a><a href="/sitemap.html">Site Map</a></li> <li><a href="/members/index.html">Members Only</a></li> <li><a href="/website-policies.html">Website Policies</a></li> <li><a href="https://doe.responsibledisclosure.com/hc/en-us" target="_blank">Vulnerability Disclosure Program</a></li> <li><a href="/contact.html">Contact Us</a></li> </ul> <div class="small">Science.gov is maintained by the U.S. Department of Energy's <a href="https://www.osti.gov/" target="_blank">Office of Scientific and Technical Information</a>, in partnership with <a href="https://www.cendi.gov/" target="_blank">CENDI</a>.</div> </nav> </footer> <script type="text/javascript"><!-- // var lastDiv = ""; function showDiv(divName) { // hide last div if (lastDiv) { document.getElementById(lastDiv).className = "hiddenDiv"; } //if value of the box is not nothing and an object with that name exists, then change the class if (divName && document.getElementById(divName)) { document.getElementById(divName).className = "visibleDiv"; lastDiv = divName; } } //--> </script> <script> /** * Function that tracks a click on an outbound link in Google Analytics. * This function takes a valid URL string as an argument, and uses that URL string * as the event label. */ var trackOutboundLink = function(url,collectionCode) { try { h = window.open(url); setTimeout(function() { ga('send', 'event', 'topic-page-click-through', collectionCode, url); }, 1000); } catch(err){} }; </script> <!-- Google Analytics --> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-1122789-34', 'auto'); ga('send', 'pageview'); </script> <!-- End Google Analytics --> <script> showDiv('page_1') </script> </body> </html>